--- flow_graph.h	2013-08-06 07:23:02.000000000 -0500
+++ flow_graph_fix1.h	2013-10-09 15:08:32.783743000 -0500
@@ -1789,7 +1789,7 @@
         if ( my_predecessors.get_item( v ) == false
              || (rval = my_successors.try_put_task(v)) == NULL ) {
             spin_mutex::scoped_lock lock(my_mutex);
-            --my_count;
+            if(my_count) --my_count;
             if ( !my_predecessors.empty() ) {
                 task *rtask = new ( task::allocate_additional_child_of( *my_root_task ) )
                     internal::forward_task_bypass< limiter_node<T> >( *this );