Error A network service error has occurred (zclient/io) at user login

[JoeLosco]

Hey all, I've been running the Open Source version of Zimbra 5.0.7 on Ubuntu 6 for a while now, and just recently we started getting the error

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

when a client attempts to log in. I saw a few posts when I searched that seemed to be for older versions and were supposed to be fixed in 5.0.5, but I'm not sure if its the same error. Things looks similar to that post but I'm not sure. While this is the case IMAP users are also not able to connect in addition to the webmail clients.

zmcontrol returns that everything looks ok. A zmcontrol stop and zmcontrol start corrects the problem for a day or so.

I've attached my zimbra.log from /var/log/ and my mailbox.log from /opt/zimbra/log/ for as much information that I think is important, but since I've trimmed it, I'm not sure if I've trimmed pertinent information.

Thanks for any and all help