Not sure if anyone's done this yet...
Rather than read about people wondering if there is a solution to the 3DFX compatibility problem, I contacted Rage who gave the following reply:-
"The Typhoon development team worked very hard to get the game working with
3DFX cards but because of the limitations of the cards, they were
unsuccessful. It was felt that there were serious problems with the 3DFX
drivers that caused the problems and since 3DFX are no longer trading,
driver updates are not likely. The Typhoon box clearly states all the cards
that are compatible with the game and you will find that 3DFX are not
listed.
I'm sorry that I can't be more positive."
So there you are - Typhoon is unlikely to ever be compatible with 3DFX so return your copy if you've got the problem. I personally took mine back to PC World, and didn't have a problem with getting my money back (just baffle them with techno-speak), even though I'd taken it out of the box!!!!