When working on the last page of the Tile Page 255 or 256, whichever one it is. The Zquest will crash if you do this:
When you are editing tiles on that tile page, and use the Ctrl-arrows for easier recoloring and you try to go past Tile Page 225, Zquest crashes!
I always recolor things on that page, and Zquest always freezes and I finally figured out this was the problem. It is just I was flying through the tiles recoloring and then I accidentally go past Tile Page 255 and it freezes.