Heres what happened.
I had a snapshot on which I was working from within a linux VM. A friend requested a clean VM as a clone of mine. So I closed / shutdown my running VM, made a copy of the Disk1.vdi along with the snapshots ({uuid}.vdi). Then I restarted the VM and did merged snapshots, deleted my home directory and made a tar+bz2 for my friend.
Then after I restored my backups, I am not able to mount my snapshot. The VM seems to boot from my version before snapshot. I cant seem to find a way to mount back my snapshot.
Any idea how to make VirtualBox see the snapshot and mount it?
I am not an expert but have coincidentally done some investigation into just this topic. You indicated that you backed up your disks (VDI and snapshots) before making changes but you did not back up the VM itself (the XML file). So you have created an incompatibility by restoring VDI and snapshots to the changed VM (that still thinks there is only a merged disk with no snapshots). Without a backup of the original VM file itself you may be out of luck. (Please see Cloning a VM With Multiple Snapshots for supporting evidence.)