Vcenter root user information gets lost

Hi,

We're running avamar 5.0.4-30 and vcenter 4.1. I've configured the connection as mentioned in the documents, and the connection works fine for a while. But after a small amount of time (perhaps about 5 mins), avamar cannot get the information from virtual center anymore. Backups will not start, if I look at existing virtual machines added to Avamar (under administration - vcenter computer - protection) the number of virtual machines is shown correctly, but all of them are called N/A. Also when trying to add new virtual server to avamar it cannot browse the vcenter at all.

Then if I go to administration and select "edit client" for vcenter server to see the window where vcenter root user has been defined (I've created separate user to vcenter computer for this) and click OK without changing anything, not changing userid or password, the connection works again. Then I can see the connected virtual machines, add new ones and start backups/restores. But again after ~5 minutes or so the connection gets lost again, and I have to open "edit client" -window again to get it working.

Any ideas what could cause the account information getting lost?

Br,

Arto