W2K3 ... do you have any service packs applied to either of these? What version of SAV CE are you running? Has it been recently updated?
As I review cases involving this issue (there aren't many), there are two suggestions to try:
1. Install the latest publicly available, non-service pack related Volume Shadow Copy Service update: http://support.microsoft.com/?kbid=891957
2. Install Service Pack 2 (contains an update that supercedes the previous but which is not available except by calling Microsoft).
VSS is a Microsoft feature that's included in Windows 2003 Server and which is used for snapshot processing for the purpose of backup and replication as well as in consistency checks and verifies of SQL databases.