As a workaround for this issue I am now using a ZFS filesystem with automatic periodic ZFS snapshots to store my VM's. If this error occurs I just revert to the last ZFS snapshot. I suspend all my VMs before taking the ZFS snapshot.
BTW, ZFS also makes it very easy to make backups of all your VMs, as you can mount a ZFS snapshot read-only.
Regards,
Gijsbert