diff -r 03af0d16c328 Lib/idlelib/run.py
--- a/Lib/idlelib/run.py	Mon Mar 26 22:14:13 2012 +0300
+++ b/Lib/idlelib/run.py	Mon Apr 02 21:42:53 2012 -0500
@@ -278,8 +278,8 @@
         rpc.RPCHandler.getresponse(self, myseq=None, wait=0.05)
 
     def exithook(self):
-        "override SocketIO method - wait for MainThread to shut us down"
-        time.sleep(10)
+        "override SocketIO method - raise error to exit"
+        raise EOFError('IDLE frontend closed.')
 
     def EOFhook(self):
         "Override SocketIO method - terminate wait on callback and exit thread"