Just to be thorough, I'm going to ask an obvious question:
You said you had both an A1200 and an A500. You're not trying to run the AGA version of Turrican on the Amiga 500, right? That will certainly crash (and often when it reaches the same point on disk).
I would see if your Amiga can load a bog standard Workbench disk, then run a mem checking utility from Aminet.
