diff --git a/classpath/java-io.cpp b/classpath/java-io.cpp
index 00d3a66979..3110c068c2 100644
--- a/classpath/java-io.cpp
+++ b/classpath/java-io.cpp
@@ -58,7 +58,7 @@ doOpen(JNIEnv* e, const char* path, int mask)
 {
   int fd = OPEN(path, mask | OPEN_MASK, S_IRUSR | S_IWUSR);
   if (fd == -1) {
-    throwNew(e, "java/lang/IOException", strerror(errno));
+    throwNew(e, "java/io/IOException", strerror(errno));
   }
   return fd;
 }
@@ -68,7 +68,7 @@ doClose(JNIEnv* e, jint fd)
 {
   int r = CLOSE(fd);
   if (r == -1) {
-    throwNew(e, "java/lang/IOException", strerror(errno));
+    throwNew(e, "java/io/IOException", strerror(errno));
   }
 }
 
@@ -81,7 +81,7 @@ doRead(JNIEnv* e, jint fd, jbyte* data, jint length)
   } else if (r == 0) {
     return -1;
   } else {
-    throwNew(e, "java/lang/IOException", strerror(errno));
+    throwNew(e, "java/io/IOException", strerror(errno));
     return 0;
   }  
 }
@@ -91,7 +91,7 @@ doWrite(JNIEnv* e, jint fd, const jbyte* data, jint length)
 {
   int r = WRITE(fd, data, length);
   if (r != length) {
-    throwNew(e, "java/lang/IOException", strerror(errno));
+    throwNew(e, "java/io/IOException", strerror(errno));
   }  
 }
 
@@ -128,7 +128,7 @@ Java_java_io_File_mkdir(JNIEnv* e, jclass, jstring path)
     if (not exists(chars)) {
       int r = ::MKDIR(chars, 0700);
       if (r != 0) {
-        throwNew(e, "java/lang/IOException", strerror(errno));
+        throwNew(e, "java/io/IOException", strerror(errno));
       }
     }
     e->ReleaseStringUTFChars(path, chars);
@@ -143,7 +143,7 @@ Java_java_io_File_createNewFile(JNIEnv* e, jclass, jstring path)
     if (not exists(chars)) {
       int fd = CREAT(chars, 0600);
       if (fd == -1) {
-        throwNew(e, "java/lang/IOException", strerror(errno));
+        throwNew(e, "java/io/IOException", strerror(errno));
       } else {
         doClose(e, fd);
       }
diff --git a/classpath/java/io/StringReader.java b/classpath/java/io/StringReader.java
index f2e2b82424..d2b536af2c 100644
--- a/classpath/java/io/StringReader.java
+++ b/classpath/java/io/StringReader.java
@@ -16,6 +16,7 @@ public class StringReader extends Reader {
       }
     }
     in.getChars(position, length, b, offset);
+    position += length;
     return length;
   }
 
diff --git a/classpath/java/lang/Throwable.java b/classpath/java/lang/Throwable.java
index 50b79130e1..01e28fd6e7 100644
--- a/classpath/java/lang/Throwable.java
+++ b/classpath/java/lang/Throwable.java
@@ -35,6 +35,10 @@ public class Throwable {
     return message;
   }
 
+  public String toString() {
+    return getClass().getName() + ": " + message;
+  }
+
   private static native Object trace(int skipCount);
 
   private static native StackTraceElement[] resolveTrace(Object trace);
diff --git a/src/jnienv.cpp b/src/jnienv.cpp
index 8fee8bac87..4cc8aca274 100644
--- a/src/jnienv.cpp
+++ b/src/jnienv.cpp
@@ -95,6 +95,12 @@ ThrowNew(Thread* t, jclass c, const char* message)
   return 0;
 }
 
+void
+DeleteLocalRef(Thread*, jobject)
+{
+  // do nothing
+}
+
 jboolean
 ExceptionCheck(Thread* t)
 {
@@ -119,6 +125,7 @@ populateJNITable(JNIEnvVTable* table)
   table->FindClass = ::FindClass;
   table->ThrowNew = ::ThrowNew;
   table->ExceptionCheck = ::ExceptionCheck;
+  table->DeleteLocalRef = ::DeleteLocalRef;
 }
 
 } // namespace vm
diff --git a/src/machine.cpp b/src/machine.cpp
index 89d237c3fd..6b38ff0ddf 100644
--- a/src/machine.cpp
+++ b/src/machine.cpp
@@ -1033,7 +1033,9 @@ parseMethodTable(Thread* t, Stream& s, object class_, object pool)
     set(t, classMethodTable(t, class_), methodTable);
   }
 
-  if (declaredVirtualCount == 0) {
+  if (declaredVirtualCount == 0
+      and (classFlags(t, class_) & ACC_INTERFACE) == 0)
+  {
     // inherit interface table and virtual table from superclass
 
     set(t, classInterfaceTable(t, class_),
diff --git a/src/run.cpp b/src/run.cpp
index 1985cfb318..bb850ed53c 100644
--- a/src/run.cpp
+++ b/src/run.cpp
@@ -208,11 +208,14 @@ resolve(Thread* t, object pool, unsigned index,
     object class_ = resolveClass(t, o, referenceClass);
     if (UNLIKELY(t->exception)) return 0;
     
+    o = 0;
     if (classFlags(t, class_) & ACC_INTERFACE) {
-      o = ::find(t, classVirtualTable(t, class_), arrayBody(t, pool, index),
-                 methodName, methodSpec);
+      if (classVirtualTable(t, class_)) {
+        o = ::find(t, classVirtualTable(t, class_), arrayBody(t, pool, index),
+                   methodName, methodSpec);
+      }
     } else {
-      for (o = 0; o == 0 and class_; class_ = classSuper(t, class_)) {
+      for (; o == 0 and class_; class_ = classSuper(t, class_)) {
         o = find(t, class_, arrayBody(t, pool, index));
       }
     }