Hello and thanks for the report. By any chance, was the GC2 ghost level loaded from a different dungeon? I.e. does the map look like a GC2 level, or does it look like it doesn't belong to GC? There's currently a bug where a ghost level might be loaded from the wrong dungeon, and the stairs then could have become misaligned.
There are two ways to salvage the game. If you feel strong enough, you can push deeper, beyond Elpuri and to Oree, where there is a portal back to GC1. That however assumes that you can survive the descent. The second option is to turn on wizard mode (should be ';', I think), and then you can use command to level-teleport back to GC1. However, if you switch on wizard mode, your game will not be scored.
I think on Linux, IVAN save files were in /usr/local/shared/ivan, but I have no idea where they would be on OSX.