I always keep an eye out for VSS related fixes for Windows 2003 because so many backup programs take advantage of the API lately. I am not sure how often this error occurs but it is good to know about ahead of time.
This one seem to replace quite a few VSS related DLLs and seems to improve upon KB
940349, which I tend to put on any Server 2003 system I have control over.
KB 949391 highlights:
Fixes Volume Shadow Copy Service error: Unexpected error IOCTL_STORAGE_QUERY_PROPERTY(
, StorageDeviceProperty) - BuildLunInfoForDrive. hr = 0x80070037. This problem may occur because VSS incorrectly hides hardware support snapshots.