Hello,
VSS and VSP history: VSP.SYS is only applicable to Windows 2000 Server and below...
Upto Windows 2000 Server Microsoft did not had any inbuilt Snapshot Provider, so Symantec provided VSP (Veritas Snapshot Provider) for Snapshot based backups, which ia known as AOFO (Paid option till BE 11.x)
Since Windows Server 2003 Microsoft started providing its own Snapshot Provider i.e. VSS (volume Shadow Copy Service)
I recomend you to uninstall AOFO form the Server and use native VSS for snapshot backups.
Open the command prompt : Browse to X:\prog. files\symantec\backup exec\agent\>
run the command removeaofo.cmd...which will remove AOFO from the system...
As its Windows Server 2003, in the jobs under AOFO select "Use Microsoft Shadow Copy Provider" and in the Drop Down select "System....."
Hope this helps....