If ti crashed on the PS2, why WOULDN'T it crash on PS3?

Different hardware.

Several of the games that aren't backwards-compatible on PS2 run perfectly on PS3. The PS1's hardware is integrated into the PS3, even on models that don't play PS2 games.

And according to the official compatibility list, the only listed issue is "When the "Continue" screen appears after the user has lost a match, and the timer reaches 0, the title hangs."

I've been having problems with the one-button fatalities. Also, can't view Kahn's treasures.

I've been playing MKT on PS2, it worked just great, no crashes, just when playing 8 players tournament, it freezes when it's over... same with when you lose the one player battle, if 10 goes down to 0, it freezes... it's just a glitch cuz of PS2 Verision. One Button Fatalities works very well, just need to press any button just right before "Finish Him/Her" disappears.
Zell