HI We have had a solution to this issue for anyone who is still experiencing this same problem.
In our case even tho there where no ISO's showing as connected to the VM's the issue was due to SnapShots that still existed for those VM's showing as mounted on 2 different DataStores those snaps where at some stage connected to ISO's mounted on different DataStoes.
The solution was to remove all the old snapshots for those VM's, once they where removed the VM no longed showed on both data stores only on its current location.
hope this helps any one who is still experiencing this same issue.
""Cheers
Gerardo.