I've installed and use zimbra in my company.

It's really a great work and it's a great piece of software. Thanks for that.

However i have a problem with my installation:
- zimbra 7 on Ubuntu 64

After a while of uptime of the server the server freezes and is not useable any more (hard reset needed )

The console prints repeating messages of:
INFO: task java:29412 blocked for more than 120 seconds.

(the PID changes with each message)

Any help or information would be great.