Do to sharing lock, a hardlink store might not delete correctly, after a restore. This will cause the backup files to remain in the store, and make a new hardlink backup fail. So after a successful restore you might want to make sure the store is removed.
From your USMT 4.0 package/library in the folder matching your architecture (x86 or x64), run the USMTUTILS.EXE tool.
Syntax: (when doing this from MDT/SCCM)
cmd.exe /c usmtutils /rd %OSDStateStorePath%
This will remove the store from all driver/partitions. Be aware though, that a reboot is needed if the store is on the OS partition.