diff --git a/base-foc/include/base/cap_alloc.h b/base-foc/include/base/cap_alloc.h
index 2aa2aaed5a..98f53bf7e5 100644
--- a/base-foc/include/base/cap_alloc.h
+++ b/base-foc/include/base/cap_alloc.h
@@ -58,7 +58,7 @@ namespace Genode {
 			 ** Cap_index_allocator interface **
 			 ***********************************/
 
-			Cap_index* alloc(size_t cnt)
+			Cap_index* alloc_range(size_t cnt)
 			{
 				Lock_guard<Spin_lock> guard(_lock);
 
@@ -80,7 +80,7 @@ namespace Genode {
 				return 0;
 			}
 
-			Cap_index* alloc(addr_t addr, size_t cnt)
+			Cap_index* alloc(addr_t addr)
 			{
 				Lock_guard<Spin_lock> guard(_lock);
 
@@ -89,17 +89,11 @@ namespace Genode {
 				 * address in capability space
 				 */
 				T* obj = reinterpret_cast<T*>(kcap_to_idx(addr));
-				T* ret = obj;
 
-				/* check whether the consecutive entries are in range and unused */
-				for (size_t i = 0; i < cnt; i++, obj++) {
-					if (obj < &_indices[0] || obj >= &_indices[SZ])
-						throw Index_out_of_bounds();
-					if (obj->used())
-						throw Region_conflict();
-					new (obj) T();
-				}
-				return ret;
+				if (obj < &_indices[0] || obj >= &_indices[SZ])
+					throw Index_out_of_bounds();
+
+				return new (obj) T();
 			}
 
 			void free(Cap_index* idx, size_t cnt)
@@ -121,6 +115,9 @@ namespace Genode {
 
 			Cap_index* kcap_to_idx(addr_t kcap) {
 				return &_indices[kcap >> Fiasco::L4_CAP_SHIFT]; }
+
+			bool static_idx(Cap_index *idx) {
+				return ((T*)idx) < &_indices[START_IDX]; }
 	};
 }
 
diff --git a/base-foc/include/base/cap_map.h b/base-foc/include/base/cap_map.h
index 320c3e7fad..28e93adf27 100644
--- a/base-foc/include/base/cap_map.h
+++ b/base-foc/include/base/cap_map.h
@@ -103,20 +103,17 @@ namespace Genode
 			 * \return     pointer to first allocated object, or zero if
 			 *             out of entries
 			 */
-			virtual Cap_index* alloc(size_t cnt) = 0;
+			virtual Cap_index* alloc_range(size_t cnt) = 0;
 
 			/**
-			 * Allocate a range of Cap_index objects at a specific
+			 * Allocate a Cap_index object at a specific
 			 * point in the capability space
 			 *
 			 * \param  kcap                address in capability space
-			 * \param  cnt                 number of objects to allocate
 			 * \throw  Index_out_of_bounds if address is out of scope
-			 * \throw  Region_conflict     if capability space entry is used
-             * \return                     pointer to first allocated object,
-			 *                             or zero if out of entries
+             * \return                     pointer to allocated object
 			 */
-			virtual Cap_index* alloc(addr_t kcap, size_t cnt) = 0;
+			virtual Cap_index* alloc(addr_t kcap) = 0;
 
 			/**
 			 * Free a range of Cap_index objects
@@ -141,6 +138,14 @@ namespace Genode
 			 * \param kcap the address in the capability space
 			 */
 			virtual Cap_index* kcap_to_idx(addr_t kcap) = 0;
+
+			/**
+			 * Returns whether a Cap_index object is from the region
+			 * controlled by core, or not.
+			 *
+			 * \param idx pointer to the Cap_index object in question
+			 */
+			virtual bool static_idx(Cap_index *idx) = 0;
 	};
 
 
@@ -226,9 +231,7 @@ namespace Genode
 			 * Create and insert a new Cap_index with a specific capability id,
 			 * and location in capability space
 			 *
-			 * Allocation of the Cap_index is done via the global
-			 * Cap_index_allocator, which might throw exceptions that aren't
-			 * caught by this method
+			 * A previously existent entry with the same id gets removed!
 			 *
 			 * \param  id   the global capability id
 			 * \param  kcap address in capability space
@@ -239,7 +242,10 @@ namespace Genode
 
 			/**
 			 * Create and insert a new Cap_index with a specific capability id
-			 * and map from given kcap to newly allocated one
+			 * and map from given kcap to newly allocated one,
+			 * if the an entry with the same id exists already,
+			 * it is returned if it points to the same kernel-object,
+			 * or gets overridden if it's already invalid.
 			 *
 			 * Allocation of the Cap_index is done via the global
 			 * Cap_index_allocator, which might throw exceptions that aren't
@@ -247,12 +253,14 @@ namespace Genode
 			 *
 			 * \param  id the global capability id
 			 * \return    pointer to the new Cap_index object, or zero
-			 *            when allocation failed
+			 *            when allocation failed, or when a valid entry
+			 *            with the same id exists and it's kernel-object
+			 *            differs to the one given by kcap
 			 */
 			Cap_index* insert_map(int id, addr_t kcap);
 
 			/**
-			 * Remove a Cap_index object
+			 * Remove (resp. invalidate) a Cap_index object
 			 *
 			 * \param i pointer to Cap_index object to remove
 			 */
diff --git a/base-foc/include/base/ipc_msgbuf.h b/base-foc/include/base/ipc_msgbuf.h
index d7d6377cef..10e0ba2b29 100644
--- a/base-foc/include/base/ipc_msgbuf.h
+++ b/base-foc/include/base/ipc_msgbuf.h
@@ -68,7 +68,7 @@ namespace Genode {
 			 * Constructor
 			 */
 			Msgbuf_base()
-			: _rcv_idx_base(cap_idx_alloc()->alloc(MAX_CAP_ARGS)), _label(0)
+			: _rcv_idx_base(cap_idx_alloc()->alloc_range(MAX_CAP_ARGS)), _label(0)
 			{
 				rcv_reset();
 				snd_reset();
diff --git a/base-foc/lib/mk/env.mk b/base-foc/lib/mk/env.mk
index 8b689c4831..8ea6467473 100644
--- a/base-foc/lib/mk/env.mk
+++ b/base-foc/lib/mk/env.mk
@@ -1,11 +1,12 @@
 SRC_CC   = env.cc context_area.cc cap_map.cc cap_alloc.cc \
-           reload_parent_cap.cc spin_lock.cc
+           reload_parent_cap.cc spin_lock.cc cap_map_remove.cc
 LIBS     = ipc heap log_console lock
 INC_DIR += $(REP_DIR)/src/base/lock $(BASE_DIR)/src/base/lock
 
 vpath env.cc               $(BASE_DIR)/src/base/env
 vpath context_area.cc      $(BASE_DIR)/src/base/env
 vpath cap_map.cc           $(REP_DIR)/src/base/env
+vpath cap_map_remove.cc    $(REP_DIR)/src/base/env
 vpath cap_alloc.cc         $(REP_DIR)/src/base/env
 vpath spin_lock.cc         $(REP_DIR)/src/base/env
 vpath reload_parent_cap.cc $(BASE_DIR)/src/base/env
diff --git a/base-foc/src/base/env/cap_map.cc b/base-foc/src/base/env/cap_map.cc
index 6a46ad7334..6c509dfba9 100644
--- a/base-foc/src/base/env/cap_map.cc
+++ b/base-foc/src/base/env/cap_map.cc
@@ -54,6 +54,10 @@ Genode::addr_t Genode::Cap_index::kcap() {
 
 Genode::uint8_t Genode::Cap_index::inc()
 {
+	/* con't ref-count index that are controlled by core */
+	if (cap_idx_alloc()->static_idx(this))
+		return 1;
+
 	spinlock_lock(&_cap_index_spinlock);
 	Genode::uint8_t ret = ++_ref_cnt;
 	spinlock_unlock(&_cap_index_spinlock);
@@ -63,6 +67,10 @@ Genode::uint8_t Genode::Cap_index::inc()
 
 Genode::uint8_t Genode::Cap_index::dec()
 {
+	/* con't ref-count index that are controlled by core */
+	if (cap_idx_alloc()->static_idx(this))
+		return 1;
+
 	spinlock_lock(&_cap_index_spinlock);
 	Genode::uint8_t ret = --_ref_cnt;
 	spinlock_unlock(&_cap_index_spinlock);
@@ -76,14 +84,9 @@ Genode::uint8_t Genode::Cap_index::dec()
 
 Genode::Cap_index* Genode::Capability_map::find(int id)
 {
-	using namespace Genode;
+	Genode::Lock_guard<Spin_lock> guard(_lock);
 
-	Lock_guard<Spin_lock> guard(_lock);
-
-	Cap_index* i = 0;
-	if (_tree.first())
-		i = _tree.first()->find_by_id(id);
-	return i;
+	return _tree.first() ? _tree.first()->find_by_id(id) : 0;
 }
 
 
@@ -96,7 +99,7 @@ Genode::Cap_index* Genode::Capability_map::insert(int id)
 	ASSERT(!_tree.first() || !_tree.first()->find_by_id(id),
 	       "Double insertion in cap_map()!");
 
-	Cap_index *i = cap_idx_alloc()->alloc(1);
+	Cap_index *i = cap_idx_alloc()->alloc_range(1);
 	if (i) {
 		i->id(id);
 		_tree.insert(i);
@@ -111,10 +114,12 @@ Genode::Cap_index* Genode::Capability_map::insert(int id, addr_t kcap)
 
 	Lock_guard<Spin_lock> guard(_lock);
 
-	ASSERT(!_tree.first() || !_tree.first()->find_by_id(id),
-	       "Double insertion in cap_map()!");
+	/* remove potentially existent entry */
+	Cap_index *i = _tree.first() ? _tree.first()->find_by_id(id) : 0;
+	if (i)
+		_tree.remove(i);
 
-	Cap_index *i = cap_idx_alloc()->alloc(kcap, 1);
+	i = cap_idx_alloc()->alloc(kcap);
 	if (i) {
 		i->id(id);
 		_tree.insert(i);
@@ -130,11 +135,8 @@ Genode::Cap_index* Genode::Capability_map::insert_map(int id, addr_t kcap)
 
 	Lock_guard<Spin_lock> guard(_lock);
 
-	Cap_index* i = 0;
-
 	/* check whether capability id exists */
-	if (_tree.first())
-		i = _tree.first()->find_by_id(id);
+	Cap_index *i = _tree.first() ? _tree.first()->find_by_id(id) : 0;
 
 	/* if we own the capability already check whether it's the same */
 	if (i) {
@@ -147,18 +149,23 @@ Genode::Cap_index* Genode::Capability_map::insert_map(int id, addr_t kcap)
 			tag = l4_task_cap_valid(L4_BASE_TASK_CAP, i->kcap());
 			if (l4_msgtag_label(tag))
 				return 0;
+			else
+				/* it's invalid so remove it from the tree */
+				_tree.remove(i);
 		} else
 			/* they are equal so just return the one in the map */
 			return i;
-	} else {
-		/* the capability doesn't exists in the map so allocate a new one */
-		i = cap_idx_alloc()->alloc(1);
-		if (!i)
-			return 0;
-		i->id(id);
-		_tree.insert(i);
 	}
 
+	/* the capability doesn't exists in the map so allocate a new one */
+	i = cap_idx_alloc()->alloc_range(1);
+	if (!i)
+		return 0;
+
+	/* set it's id and insert it into the tree */
+	i->id(id);
+	_tree.insert(i);
+
 	/* map the given cap to our registry entry */
 	l4_task_map(L4_BASE_TASK_CAP, L4_BASE_TASK_CAP,
 				l4_obj_fpage(kcap, 0, L4_FPAGE_RWX),
@@ -167,21 +174,6 @@ Genode::Cap_index* Genode::Capability_map::insert_map(int id, addr_t kcap)
 }
 
 
-void Genode::Capability_map::remove(Genode::Cap_index* i)
-{
-	using namespace Genode;
-
-	Lock_guard<Spin_lock> guard(_lock);
-
-	if (i) {
-		Cap_index* e = _tree.first() ? _tree.first()->find_by_id(i->id()) : 0;
-		if (e == i)
-			_tree.remove(i);
-		cap_idx_alloc()->free(i, 1);
-	}
-}
-
-
 Genode::Capability_map* Genode::cap_map()
 {
 	static Genode::Capability_map map;
diff --git a/base-foc/src/base/env/cap_map_remove.cc b/base-foc/src/base/env/cap_map_remove.cc
new file mode 100644
index 0000000000..6886a2d22f
--- /dev/null
+++ b/base-foc/src/base/env/cap_map_remove.cc
@@ -0,0 +1,30 @@
+/*
+ * \brief  Mapping of Genode's capability names to kernel capabilities.
+ * \author Stefan Kalkowski
+ * \date   2010-12-06
+ *
+ * This is a Fiasco.OC-specific addition to the process enviroment.
+ */
+
+/*
+ * Copyright (C) 2010-2012 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <base/cap_map.h>
+
+void Genode::Capability_map::remove(Genode::Cap_index* i)
+{
+	using namespace Genode;
+
+	Lock_guard<Spin_lock> guard(_lock);
+
+	if (i) {
+		Cap_index* e = _tree.first() ? _tree.first()->find_by_id(i->id()) : 0;
+		if (e == i)
+			_tree.remove(i);
+		cap_idx_alloc()->free(i, 1);
+	}
+}
diff --git a/base-foc/src/base/ipc/ipc.cc b/base-foc/src/base/ipc/ipc.cc
index 18d4f33214..2019ad30b0 100644
--- a/base-foc/src/base/ipc/ipc.cc
+++ b/base-foc/src/base/ipc/ipc.cc
@@ -192,7 +192,7 @@ void Ipc_istream::_wait()
 Ipc_istream::Ipc_istream(Msgbuf_base *rcv_msg)
 :
 	Ipc_unmarshaller(&rcv_msg->buf[0], rcv_msg->size()),
-	Native_capability(cap_map()->find(Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_BADGE])),
+	Native_capability((Cap_index*)Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_BADGE]),
 	_rcv_msg(rcv_msg)
 {
 	_read_offset = sizeof(l4_mword_t);
diff --git a/base-foc/src/base/ipc/pager.cc b/base-foc/src/base/ipc/pager.cc
index 801cdc05a7..923f0fdf2f 100644
--- a/base-foc/src/base/ipc/pager.cc
+++ b/base-foc/src/base/ipc/pager.cc
@@ -113,5 +113,6 @@ void Ipc_pager::acknowledge_wakeup()
 
 
 Ipc_pager::Ipc_pager()
-: Native_capability(cap_map()->find(Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_BADGE])), _badge(0) { }
+: Native_capability((Cap_index*)Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_BADGE]),
+  _badge(0) { }
 
diff --git a/base-foc/src/base/pager/pager.cc b/base-foc/src/base/pager/pager.cc
index 1030f792ca..2473efeab2 100644
--- a/base-foc/src/base/pager/pager.cc
+++ b/base-foc/src/base/pager/pager.cc
@@ -160,7 +160,13 @@ Pager_entrypoint::Pager_entrypoint(Cap_session           *cap_session,
 }
 
 
-void Pager_entrypoint::dissolve(Pager_object *obj) { remove(obj); }
+void Pager_entrypoint::dissolve(Pager_object *obj)
+{
+	/* cleanup at cap session */
+	_cap_session->free(obj->Object_pool<Pager_object>::Entry::cap());
+
+	remove(obj);
+}
 
 
 Pager_capability Pager_entrypoint::manage(Pager_object *obj)
diff --git a/base-foc/src/base/thread/thread_start.cc b/base-foc/src/base/thread/thread_start.cc
index 7bf710e0f2..bec30a5e59 100644
--- a/base-foc/src/base/thread/thread_start.cc
+++ b/base-foc/src/base/thread/thread_start.cc
@@ -29,9 +29,9 @@ void Thread_base::_deinit_platform_thread()
 {
 	using namespace Fiasco;
 
-	int id = l4_utcb_tcr_u(_context->utcb)->user[UTCB_TCR_BADGE];
+	Cap_index *i = (Cap_index*)l4_utcb_tcr_u(_context->utcb)->user[UTCB_TCR_BADGE];
+	cap_map()->remove(i);
 	env()->cpu_session()->kill_thread(_thread_cap);
-	cap_map()->remove(cap_map()->find(id));
 }
 
 
@@ -57,18 +57,9 @@ void Thread_base::start()
 	_tid = state.kcap;
 	_context->utcb = state.utcb;
 
-	try {
-		l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_BADGE]      = state.id;
-		l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_THREAD_OBJ] = (addr_t)this;
-
-		/* there might be leaks in the application */
-		cap_map()->remove(cap_map()->find(state.id));
-
-		/* we need to manually increase the reference counter here */
-		cap_map()->insert(state.id, state.kcap)->inc();
-	} catch(Cap_index_allocator::Region_conflict) {
-		PERR("could not insert id %x", state.id);
-	}
+	Cap_index *i = cap_map()->insert(state.id, state.kcap);
+	l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_BADGE]      = (unsigned long) i;
+	l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_THREAD_OBJ] = (addr_t)this;
 
 	/* register initial IP and SP at core */
 	addr_t thread_sp = (addr_t)&_context->stack[-4];
diff --git a/base-foc/src/core/cap_session_component.cc b/base-foc/src/core/cap_session_component.cc
index 29ddb85cfd..2323a76455 100644
--- a/base-foc/src/core/cap_session_component.cc
+++ b/base-foc/src/core/cap_session_component.cc
@@ -71,21 +71,6 @@ void Cap_mapping::map(Native_thread_id task)
 }
 
 
-void Cap_mapping::unmap()
-{
-	using namespace Fiasco;
-
-	if (!local)
-		return;
-
-	l4_msgtag_t tag = l4_task_unmap(L4_BASE_TASK_CAP,
-	                                l4_obj_fpage(local->kcap(), 0, L4_FPAGE_RWX),
-	                                L4_FP_ALL_SPACES | L4_FP_DELETE_OBJ);
-	if (l4_msgtag_has_error(tag))
-		PERR("unmapping cap failed");
-}
-
-
 Cap_mapping::Cap_mapping(bool alloc, Native_thread_id r)
 : local(alloc ? _get_cap() : 0), remote(r)
 {
@@ -105,7 +90,6 @@ Cap_mapping::Cap_mapping(Core_cap_index* i, Native_thread_id r)
 Cap_mapping::~Cap_mapping()
 {
 	if (local) {
-		unmap();
 		cap_map()->remove(local);
 	}
 }
@@ -164,6 +148,7 @@ Native_capability Cap_session_component::alloc(Cap_session_component *session,
 	} catch (Cap_id_allocator::Out_of_ids) {
 		PERR("Out of IDs");
 	}
+
 	return cap;
 }
 
@@ -189,15 +174,7 @@ void Cap_session_component::free(Native_capability cap)
 	if (idx->session() != this)
 		return;
 
-	l4_msgtag_t tag = l4_task_unmap(L4_BASE_TASK_CAP,
-	                                l4_obj_fpage(idx->kcap(), 0, L4_FPAGE_RWX),
-	                                L4_FP_ALL_SPACES | L4_FP_DELETE_OBJ);
-	if (l4_msgtag_has_error(tag))
-		PERR("destruction of ipc-gate %lx failed!", (unsigned long) idx->kcap());
-
-	unsigned long id = idx->id();
-	cap_map()->remove(idx);
-	platform_specific()->cap_id_alloc()->free(id);
+	idx->dec();
 }
 
 
@@ -232,6 +209,32 @@ void Cap_id_allocator::free(unsigned long id)
 }
 
 
+void Genode::Capability_map::remove(Genode::Cap_index* i)
+{
+	using namespace Genode;
+	using namespace Fiasco;
+
+	Lock_guard<Spin_lock> guard(_lock);
+
+	if (i) {
+		Core_cap_index* e = static_cast<Core_cap_index*>(_tree.first() ? _tree.first()->find_by_id(i->id()) : 0);
+		if (e == i) {
+
+			l4_msgtag_t tag = l4_task_unmap(L4_BASE_TASK_CAP,
+			                                l4_obj_fpage(i->kcap(), 0, L4_FPAGE_RWX),
+			                                L4_FP_ALL_SPACES | L4_FP_DELETE_OBJ);
+			if (l4_msgtag_has_error(tag))
+				PERR("destruction of ipc-gate %lx failed!", (unsigned long) i->kcap());
+
+
+			platform_specific()->cap_id_alloc()->free(i->id());
+			_tree.remove(i);
+		}
+		cap_idx_alloc()->free(i, 1);
+	}
+}
+
+
 Genode::Cap_index_allocator* cap_idx_alloc()
 {
 	static Genode::Cap_index_allocator_tpl<Core_cap_index, 20*1024> _alloc;
diff --git a/base-foc/src/core/include/cap_mapping.h b/base-foc/src/core/include/cap_mapping.h
index 3f0fede070..7f9b94f6cb 100644
--- a/base-foc/src/core/include/cap_mapping.h
+++ b/base-foc/src/core/include/cap_mapping.h
@@ -55,11 +55,6 @@ namespace Genode {
 			 * \param task capability of task to map to
 			 */
 			void map(Native_task task);
-
-			/**
-			 * Unmap all child mappings
-			 */
-			void unmap();
 	};
 }
 
diff --git a/base-foc/src/core/thread_start.cc b/base-foc/src/core/thread_start.cc
index c0ac260f4f..217af26935 100644
--- a/base-foc/src/core/thread_start.cc
+++ b/base-foc/src/core/thread_start.cc
@@ -50,7 +50,7 @@ void Thread_base::start()
 	pt->pager(platform_specific()->core_pager());
 
 	_context->utcb = pt->utcb();
-	l4_utcb_tcr_u(pt->utcb())->user[UTCB_TCR_BADGE]      = pt->gate().local->id();
+	l4_utcb_tcr_u(pt->utcb())->user[UTCB_TCR_BADGE]      = (unsigned long) pt->gate().local;
 	l4_utcb_tcr_u(pt->utcb())->user[UTCB_TCR_THREAD_OBJ] = (addr_t)this;
 
 	pt->start((void *)_thread_start, _context->stack);
diff --git a/base-foc/src/platform/_main_helper.h b/base-foc/src/platform/_main_helper.h
index 7a75b74df6..d12ea912b1 100644
--- a/base-foc/src/platform/_main_helper.h
+++ b/base-foc/src/platform/_main_helper.h
@@ -28,19 +28,10 @@ enum { MAIN_THREAD_CAP_ID = 1 };
 static void main_thread_bootstrap() {
 	using namespace Genode;
 
-	/**
-	 * Unfortunately ldso calls this function twice. So the second time when
-	 * inserting the main thread's gate-capability an exception would be raised.
-	 * At least on ARM we got problems when raising an exception that early,
-	 * that's why we first check if the cap is already registered before
-	 * inserting it.
-	 */
-	Cap_index *idx = cap_map()->find(MAIN_THREAD_CAP_ID);
-	if (!idx) {
-		Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_BADGE]      = MAIN_THREAD_CAP_ID;
-		Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_THREAD_OBJ] = 0;
-		cap_map()->insert(MAIN_THREAD_CAP_ID, Fiasco::MAIN_THREAD_CAP)->inc();
-	}
+	Cap_index *i
+		= cap_map()->insert(MAIN_THREAD_CAP_ID, Fiasco::MAIN_THREAD_CAP);
+	Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_BADGE] = (unsigned long) i;
+	Fiasco::l4_utcb_tcr()->user[Fiasco::UTCB_TCR_THREAD_OBJ] = 0;
 }
 
 
diff --git a/base-foc/src/test/cap_integrity/main.cc b/base-foc/src/test/cap_integrity/main.cc
index 95eaaf57ca..c414b7b469 100644
--- a/base-foc/src/test/cap_integrity/main.cc
+++ b/base-foc/src/test/cap_integrity/main.cc
@@ -25,7 +25,7 @@ int main(int argc, char **argv)
 
 	enum { COUNT = 1000 };
 
-	Cap_index*       idx = cap_idx_alloc()->alloc(COUNT);
+	Cap_index*       idx = cap_idx_alloc()->alloc_range(COUNT);
 	Native_thread_id tid = env()->ram_session_cap().dst();
 
 	/* try the first 1000 local name IDs */
diff --git a/ports-foc/src/lib/l4lx/include/dataspace.h b/ports-foc/src/lib/l4lx/include/dataspace.h
index 743d93ec82..49512d431d 100644
--- a/ports-foc/src/lib/l4lx/include/dataspace.h
+++ b/ports-foc/src/lib/l4lx/include/dataspace.h
@@ -50,7 +50,7 @@ namespace L4lx {
 			          Genode::size_t                 size,
 			          Genode::Dataspace_capability   ds)
 			: _name(name), _size(size), _cap(ds),
-				_ref(Genode::cap_idx_alloc()->alloc(1)->kcap()) {}
+				_ref(Genode::cap_idx_alloc()->alloc_range(1)->kcap()) {}
 
 
 			/***************
diff --git a/ports-foc/src/lib/l4lx/include/vcpu.h b/ports-foc/src/lib/l4lx/include/vcpu.h
index 7416c80cd6..8cd687ba94 100644
--- a/ports-foc/src/lib/l4lx/include/vcpu.h
+++ b/ports-foc/src/lib/l4lx/include/vcpu.h
@@ -88,16 +88,10 @@ namespace L4lx {
 				_tid = state.kcap;
 				_context->utcb = state.utcb;
 
-				try {
-					l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_BADGE]      = state.id;
-					l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_THREAD_OBJ] = (addr_t)this;
-					l4_utcb_tcr_u(state.utcb)->user[0] = state.kcap; /* L4X_UTCB_TCR_ID */
-
-					/* we need to manually increase the reference counter here */
-					cap_map()->insert(state.id, state.kcap)->inc();
-				} catch(Cap_index_allocator::Region_conflict) {
-					PERR("could not insert id %x", state.id);
-				}
+				Cap_index *i = cap_map()->insert(state.id, state.kcap);
+				l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_BADGE] = (unsigned long) i;
+				l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_THREAD_OBJ] = (addr_t)this;
+				l4_utcb_tcr_u(state.utcb)->user[0] = state.kcap; /* L4X_UTCB_TCR_ID */
 
 				/* register initial IP and SP at core */
 				addr_t stack = (addr_t)&_context->stack[-4];
diff --git a/ports-foc/src/lib/l4lx/l4_re_c_util_cap.cc b/ports-foc/src/lib/l4lx/l4_re_c_util_cap.cc
index ece56ebb39..62114e6970 100644
--- a/ports-foc/src/lib/l4lx/l4_re_c_util_cap.cc
+++ b/ports-foc/src/lib/l4lx/l4_re_c_util_cap.cc
@@ -28,7 +28,7 @@ extern "C" {
 
 	l4_cap_idx_t l4re_util_cap_alloc(void)
 	{
-		l4_cap_idx_t ret = Genode::cap_idx_alloc()->alloc(1)->kcap();
+		l4_cap_idx_t ret = Genode::cap_idx_alloc()->alloc_range(1)->kcap();
 
 		if (DEBUG)
 			PDBG("ret=%lx", ret);
diff --git a/ports-foc/src/lib/l4lx/l4lx_task.cc b/ports-foc/src/lib/l4lx/l4lx_task.cc
index 28a8d483ed..01973e8811 100644
--- a/ports-foc/src/lib/l4lx/l4lx_task.cc
+++ b/ports-foc/src/lib/l4lx/l4lx_task.cc
@@ -85,7 +85,7 @@ int l4lx_task_number_free(l4_cap_idx_t task)
 int l4lx_task_get_new_task(l4_cap_idx_t parent_id,
                            l4_cap_idx_t *id)
 {
-	*id = Genode::cap_idx_alloc()->alloc(1)->kcap();
+	*id = Genode::cap_idx_alloc()->alloc_range(1)->kcap();
 	return 0;
 }