diff -r 713db33a4ebc Lib/idlelib/rpc.py
--- a/Lib/idlelib/rpc.py	Sat Mar 10 23:43:12 2012 +0100
+++ b/Lib/idlelib/rpc.py	Sun Mar 11 16:33:09 2012 -0500
@@ -185,7 +185,10 @@
         method = getattr(obj, methodname)
         try:
             if how == 'CALL':
-                ret = method(*args, **kwargs)
+                try:
+                    ret = method(*args, **kwargs)
+                except Exception as exc:
+                    return ("CALLEXC", exc)
                 if isinstance(ret, RemoteObject):
                     ret = remoteref(ret)
                 return ("OK", ret)
@@ -257,6 +260,9 @@
         if how == "ERROR":
             self.debug("decoderesponse: Internal ERROR:", what)
             raise RuntimeError(what)
+        if how == "CALLEXC":
+            self.debug("decoderesponse: Call Exception:", what)
+            raise what
         raise SystemError(how, what)
 
     def decode_interrupthook(self):