VM snapshot/revert operation : Deleting a VM doesn't delete a VHD file

Hi,

I have explained the issue below to reproduce:

1)There are 2 physical servers in the pool.
2)Import a VM to sever A's local storage.Hence you can see 1 VHD file in the local storage now.
3)Now take a snapshot of this VM ,(lets say name of snapshot is snap1)
4)The above creates 2 other VHD files in the local storage
5)Now shutdown the VM and do "move VM" operation from xencenter from server A's local storage to server B's local storage.Now I will have 2 VHD files in server A's local storage and 1 VHD file in server B's local storage.The VM gets moved on to server B as expected.
6)Now I do a revert snapshot operation using snap1 .This makes VM to get reverted and it moves on to Server A since snap1 was taken when the VM was on server A.

Till here everything is fine.

7)Now delete the VM from xenserver along with its snapshot .This will delete all VHD files from server A's local storage as expected but it fails to delete 1 VHD file that was on server B's local storage .

So my question when I have deleted VM along with snapshot option ,why do the VHD file on server B's local storage does not get deleted .This would remain as stale entry and wastes storage consumption on server B's local storage.