diff --git a/src/allmydata/immutable/downloader/fetcher.py b/src/allmydata/immutable/downloader/fetcher.py
index 4e8b7f926..130bb93dc 100644
--- a/src/allmydata/immutable/downloader/fetcher.py
+++ b/src/allmydata/immutable/downloader/fetcher.py
@@ -63,13 +63,14 @@ class SegmentFetcher(object):
         self._running = True
 
     def stop(self):
-        log.msg("SegmentFetcher(%r).stop" % self._node._si_prefix,
-                level=log.NOISY, parent=self._lp, umid="LWyqpg")
-        self._cancel_all_requests()
-        self._running = False
-        # help GC ??? XXX
-        del self._shares, self._shares_from_server, self._active_share_map
-        del self._share_observers
+        if self._running:
+            log.msg("SegmentFetcher(%r).stop" % self._node._si_prefix,
+                    level=log.NOISY, parent=self._lp, umid="LWyqpg")
+            self._cancel_all_requests()
+            self._running = False
+            # help GC ???
+            del self._shares, self._shares_from_server, self._active_share_map
+            del self._share_observers
 
 
     # called by our parent _Node
diff --git a/src/allmydata/immutable/downloader/node.py b/src/allmydata/immutable/downloader/node.py
index a58d82a01..102d29a0a 100644
--- a/src/allmydata/immutable/downloader/node.py
+++ b/src/allmydata/immutable/downloader/node.py
@@ -533,10 +533,11 @@ class DownloadNode(object):
         self._segment_requests = [t for t in self._segment_requests
                                   if t[2] != cancel]
         segnums = [segnum for (segnum,d,c,seg_ev,lp) in self._segment_requests]
+
         # self._active_segment might be None in rare circumstances, so make
         # sure we tolerate it
         if self._active_segment and self._active_segment.segnum not in segnums:
-            seg, self._active_segment = self._active_segment, None##True # XXX None for real
+            seg, self._active_segment = self._active_segment, None
             seg.stop()
             self._start_new_segment()