At a guess, one time the program ran and the job was killed unexpectedly before it did its cleanup.

If that is the case the best solution is probably to clean it up again as root, then run as "cbsrepl" and deliberately leave the memory segment there. Now it will work as cbsrepl and root indefinitely as long as nobody cleans up the existing memory segment. (But you'll need to deal with this when the machine next reboots, talk to your sysadmin about setting up an init script to create the memory segment as cbsrepl to avoid it next time.)