Hi,
I would like to add some points here,
1. Create a new user as Backup exec user and provide Local/Domain Admin rights.
2 - Repair Database :
http://support.veritas.com/docs/265180
if above steps fails to work then,
3. Reload from base :
http://support.veritas.com/docs/254014
We hope this information helps, if you have any other questions please respond to the post and we will be more than happy to assist you further.