No idea... I am having the same error on zmfixperms on a 4.5.6 install with Fedora 5. I currently have 4.5.6 working on Fedora 4 but am trying to test a move to a newer server with Zero luck so far.
I do have zimbra installed, services are up, but I had an error checking the queue...
Error msg with queue is, Message: system failure: exception during auth, which led me to
Mail Queue Monitoring - Zimbra :: Wiki
The solution for troubleshooting the queue is to run zmfixperms, but that is not working correctly yet >

When run as the user zimbra it just comes up with permission problems "Operation not permitted" or "Permission denied". When run as root, it errors with cannot access *perdition-1.17 - No such file or directory. The zmfixperms file is looking for perdition-1.17, but only 1.17.1 exists.
I am assuming zmfixperms needs to be run as root? If so, maybe there is an error in the zmfixperms script in the 4.5.6 FC5 build?
Andy