Hi Alex.
I was not able to solve the problem. I setup two completely new servers in a test environment leading to exacly the same result. I also opened a case at Symantec. At first they advised to try some things which also did not solve the problem but then they stopped responding to my latest email which is about one week ago.
Sorry to say but I do not trust in reliability of GRT any longer and so dropped it altogether. I don't like to take the risk that our customers are making backups which they are not able to restore in an emergancy case. This is the best way to loose customers.
To restore individual mailboxes I now use a Recovery Storage Group which works as expected.
I'm quite disappointed about the current performance of Symantec as we also have serious problems with Endpoint Protection 11.0. Anytime you reach the point where the attempt to save additional costs has direct imapct on the quality of your products.
Regards,
grubi