Thanks for the link!
One of the cracked versions crashed more often, if I remember correctly. I think this is because it was an earlier version of the game executable. If you press 'V' in-game it shows the version string. The cracked version I found online gives this version string:
K240 - VERSION 1.886, 20-5-94 13:25
But on the disks from my original UK retail copy of the game, it gives this version:
K240 - VERSION 2.000, 7-6-94 11:15
That version seems to crash less often. When I play, I use my retail copy and look up the manual protection codes on my own website
I'm wondering what the difference was. Was version 1.886 a review copy sent to magazines? There was a rumour that one of the Amiga magazines had a guy who would leak review copies to pirate groups.