Seems like you have a corrupt RSM database
follow the article below
I could not find the appropriate article for BESR but these should do the trick as the issue is with RSM and VSS writers and not with the BESR application.
NTbackup does not use VSS
http://support.veritas.com/docs/274993
http://support.veritas.com/docs/231941
Microsoft KB article:
http://support.microsoft.com/?id=235032
http://support.microsoft.com/?id=288856