Sorry, you are having problems.
Could you have a look at the client log file ( described here Having problems with UrBackup? Please read before posting ) if CBT actually failed (CBT reset)?
Also if this CBT reset happend only once (e.g. because the shadow copy was deleted really fast after creation), it would not be that much of an issue… (if it happens regularily it is annoying). I guess the Windows event log entries w.r.t. HarddiskVolumeShadowCopy104 would also be interesting.