Keeps losing linked disk

[Granta]

I had cause to delete a linked clone (not the files ..) to investigate something. Now, having re-added the clone (successfully ..), I'm having to keep adding the clone's disk snapshot to the list of hard disks (it appears under the parent as expected).

A restart of the application retains the added disk and the VM boots, but it seems that whenever I restart the host (I normally just sleep/resume), the snapshotted disk disappears from the list of registered disks and has to be added by hand again. The 'add' doesn't seem to be retained through a host restart - or at least I've only so far seen the phenomenon after restarts. Will add to the report if I see it on other occasions.