[Zope] Locked out of root ZMI

I have an zope instance where I try to log into the ZMI and it won't accept my password. The password has not been changed. I can log into other parts of the ZMI where there a folders with their own acl_users folder. It just fails when I try to login to the root ZMI. I'm running site root, OpenSSL, Apache 1.3.22 as a caching proxy, and a few local roles in the intranet folder (a CMF site). Mozilla returns an error "intranet.company.com recieved a message with incorrect Message Authentication Code" Not too long ago, I packed the database. Is it the caching proxy or some other cause?