Okay, disregard.
Here was the issue:
The old backup server (Server 2003 w/Backup Exec 12) was removed and is no longer. Left behind were several folks who were not migrated to the new backup server. Despite that, they're DLO agents were still backing up to the original .dlo databases.
Then one of the users suffered a hard drive failure before he could be moved to the new server/DLO agent. The .dlo file, being encrypted from the original backup server, couldn't be accessed with the new DLO agent since it was using a different encryption key.
In order to restore the .dlo database I had to run the following:
C:\Program Files\Symantec\Symantec DLO: DLOCommandu -EmergencyRestore "\\ServerName\DLOStorage\DomainName-UserName\.dlo" -W myp@ssword -AP \\ServerName\ShareName\restoreddata
So far the restore seems to be working (lots of data so it's not finished yet as of this message.)
Of course, if you don't have the password that was used to encrypt the original .dlo databases you may be in trouble. Before I tracked down the old password I was attempting to find a way to "hack" them, but was not successful.
Hope this helps someone!
-Brett