Some KQ7 rooms set up global state and may not reset that state properly if you teleport out (using the debugger). This causes a crash down the road (so far down the road, in fact, that you wouldn't make the connection between the two events). It only happens if you edit variable 13 directly, not when a script calls the newRoom: method. This, of course, means that the KQ7 debug script works, since it does it the proper way. But that is not so easy to do by hand.