Backup agent has nothing to do with DLO agent. Also please try this artilce
http://support.veritas.com/docs/348013
If still have the same issue then please do the local install of DLO
How to do local install of DLO:
c:\Program Files\Symantec\Backup Exec\Agents\DLO
copy the dlo folder to the xp and 7 machine and run the setup.exe