Reposting a thread with same title as Chirpy happened to lock out previous thread.
Forwarders and Catchall Bug
Vote for this (in case you use Chirpy's Dictionary Attack --- as anyone can by pass your settings even if you do not allow catchall fiddling) as the same is status quo after 8 months of reporting and 2 votes. It's a real pain attending support tickets due to bugs:

http://bugzilla.cpanel.net/show_bug.cgi?id=2499

Hope this thread is also not locked out.

Anup