diff -r 23511e4da055 -r a7e901209005 src/Pure/Concurrent/future.ML
--- a/src/Pure/Concurrent/future.ML	Mon Jul 27 15:53:43 2009 +0200
+++ b/src/Pure/Concurrent/future.ML	Mon Jul 27 16:08:41 2009 +0200
@@ -347,7 +347,6 @@
 
 fun join_next deps = (*requires SYNCHRONIZED*)
   if null deps then NONE
-  else if overloaded () then (worker_wait scheduler_event; join_next deps)
   else
     (case change_result queue (Task_Queue.dequeue_towards deps) of
       (NONE, []) => NONE