Get the session ID of the backup of Exchange 2010, and from the command line on the cell manager, run
omnidb -session [session_id] -detail Do not include [ ] marks
Look for a line that says 'Protection' and make sure that the Backup session was protected
If a session is not protected, a Daily Maintenance run every day at noon local time will look for any sessions that have no protection, and, if any are found, removes the catalog, eliminating the ability to see the Backups in the Restore GUI
Also, try 'Restore by Session' just to see if you see the session ID of the backup
Are you trying to Restore from a Backup, or from an Object Copy?
Finally, this may have something to do with how Exchange was backed up. I checked lab cases, found done very close to your problem with DP 6.21 for which a test binary was issued. It does not appear that this has yet to be ported to a General Release patch yet
You should probably open a case with DP support for this issue
