--- a/hotspot/src/share/vm/runtime/thread.cpp	Thu Jun 03 14:20:27 2010 -0700
+++ b/hotspot/src/share/vm/runtime/thread.cpp	Fri Jun 04 11:18:04 2010 -0700
@@ -2797,6 +2797,7 @@
   _task  = NULL;
   _queue = queue;
   _counters = counters;
+  _buffer_blob = NULL;
 
 #ifndef PRODUCT
   _ideal_graph_printer = NULL;