Hi,
Which version of Backup Exec are you using?
If the version is 10.1, make sure that Hotfix 6 is installed:
10.1.5629 Hotfix 6 - SQL 2005 (Yukon) support for Backup Exec 10d
http://support.veritas.com/docs/280204
The Remote Agent on the SQL server needs to be updated after the installation of the patch on the media server.
Is SQL 2005 clustered?
Regards,
Padmaja