Just to clarify the above set up, I have:
Backup Server
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Windows 2003
Backup Exec 9.1 with SQL Agent and OFO
Virtual SQL Server
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Windows 2003
SQL Server 2000
Remote Backup Agent with OFO enabled
(host physical machine is Windows 2003 running Virtual Server 2005 R2)
The backup server is unable to see the SQL databases as part of Shadow Copy Components on the virtual SQL server.
Thanks for any suggestions!