The VSS application writer or the VSS provider is in a bad
state. Either it was already in a bad state or it entered a bad state during
the current operation. (ID 30111)
One Solution: This is just a quick one to rule out before looking at the more complicated things that can go wrong with the VSS provider.
Verify that the restore isn't trying to write to files that already exist on the target server.
Seems to me that perhaps a more descriptive error message...something like...say..."File already exists" would fit the bill here, but absent that, I'm loving how much better behaved DPM 2010 is.