E8602 EC127 while backing up SQL databases

[dcave]

I'm trying to back up 19 SQL 8.0 databases using Arcserve 2000 running on the local machine, which is a Win2K SP2 server. I'm getting the error message E8602 - Failed to read from database (EC=Backup agent error (127) - Error at virtual device set.) I've checked the VDI.LOG file, and it gives the error "Error on DBASQL70TID2956VD0, Error at triggerabort: invoked".
I've checked the compatibility modes of the databases (all are 8) and changed the protocol to TCP described in FAQ861-2582, but with no joy. Any ideas?