GroupWise 5.5 Old Archives deleted

Old archives, when restored to the GroupWise mailbox are being deleted on one user's system. When I log in, with a different post office, I have no problems on his PC in restoring archived e-mails. I checked another person who is on the same post office as the person having the trouble, and he is successful in restoring an old archived e-mail. The system is set to delete e-mails older than 60 days, but that is only supposed to happen when re-starting GroupWise. The client install is fine, because I was able to restore my archived e-mails without them being deleted from his system.