"and force the hostname to be localhost instead of the actual hostname"....
Does this mean that the hostname has potentially changes as far as rabbit is concerned??
Have you seen this append - http://community.zenoss.org/message/71139#71139 ?
It still sounds like rabbit is actively refusing to respond to zenhub so it has to be some sort of authentication mis-match.
Do you now have lots of processes if you do ps -ef / grep rabbit ???
Cheers,
Jane