Error in MIB-Browser

Since the last update to 6010 i regularly run into an error message displayed in the MIB-browser.

I'm querying a device several times, and then suddenly a message window appeas with the following error message:

problem iii [object error]

After this message the only way to use the mib-browser again is going back to the admin page and restart the mib-browser.

Anybody know where this is coming from .. and more importantly ... how to fix this?