preauth and gdpak stopped working for 1 domain

[mahalito]

I am in a bit of trouble.

we are running zimbra 6.0.10 and have many different domains.
we use preauth inside our portal and have been for over a year without any problems.
On Friday, one of our domain stopped working with preauth. trying to test it I recreated a new key (zmprov gdpak -f domain.com) but that didn't solve the problem.
the error I found in the logs is
error=authentication failed for user@domain.com, preauth mismatch;

Couple of other facts:
- outlook connector still works for those users
- Note that all the other domains are working flawlessly so far.
- our licenses are expiring on 9/1

I have a absolutely no idea what is happening but I have some less then happy users and vmware has yet to answer my support request (lovely) I would appreciate ANY ideas/thoughts.