[figuser]

Hello,
I upgraded our Zimbra 4.0.4 install to 4.5 GA over the weekend. Every thing was working find for a day then all of a sudden, this morning, all the users started receivng the following error when they tried to login

An unknown application error has occurred. Please correct any errors and retry. If the problem persists, please contact your System Administrator. (INVALID_PDU)

Nothing has changed in the env or the machine.

Zimbra is running on FC5 with all the updates.

I cant even login to the admin console.. the password is accepted but then nothing shows up.

I tried, rebooting, reinstalling 4.5 GA but none of it helped. The zimbra logs are not showing any errors and all the services apprear to be running. BTW this is the Open source version...

The classic client reports

A network service error has occurred (zclient/io).

I have tried accessing my account using Thunderbird through IMAP and that is not working also. Thunderbird doesnt give me an error but no mails show up..

There are about 80 users on the system. Total mailbox size for all the users combined is about 4 GB. The server is a 3.0 PentiumD 1 GB ram. 164 GB HDD

Any ideas?