Bosch571

Hi X-com sometimes crashes in tactical mode, this always happens at the same time e.g. when a soldier stands on the door of the landings craft, he can walk over it without a problem and going up a lift also crashes the game, and there are more ways to crash a game. I try to avoid these things but there are simply to many of them, happens on both my XP computers, but before I upgraded to XP (came from 98) it worked flawlessly. Any way to fix this?