I have the same exact problem. The suggestions in the thread are not viable. You see, there is a reason for us to be doing a snapshot of the DB machine. We WANT the snapshot to happen. Doing away with it is not an option. Also, it is not anybody's fault by Microsoft, apparently. Check Knowledge base article 951288. It is a problem with Microsoft's VSS itself. This is really annoying and dangerous. All differential backups do work, but they are nearly useless, since they are based on a "full" backup that does actually exist. The alternative is to restore from the snapshot, and then use the differentials to bring the DB up to date. Not a good option for us.

So, in short:

1- We need to maintain the snapshots

2- Is seems to be a Microsoft issue

3- We need to prevent SQL from registering the snapshots as viable, valid full DB backups

OR

4- We need SQL to ignore the snapshots when doing transaction log and differential backups

Help appreciated. Raphael