Hi Michael,
I would like to ask few questions about this
1. From where did you restore? Was it initiated through NSPOG?
2. After restoring and adding the VM to inventory, did you check in edit settings and by clicking on the harddisk, it displays on the right side whether it is thick or thin?
Because, I just created a dummy VM (thin disks), backed up, deleted the VM from disk, restored and checked. It was thin.
Let us know if you are still facing this issue...
Thanks,
Arun