"Zone save per level" doesn't work

[evouga]

Consider the following (sadly, all-too-frequent) chain of events:

1. Get to, say level 4 of some dungeon.
2. TOME segfaults.
3. I restart tome and load my game, only to find that I have to start over again from level 1.

I would have thought "Zone save per level" would mean I would only have to start over from level 4, but this is not the case for some reason.