Raimi fell in love with S-M2's temp score apparently, and didnt want Elfman to change it for the final film. This hurt Elfman's ego, and they had a falling out. Now Elfman says he wont work with Sam again, and that Sam "wasnt even the same person" by the end of S-M2's production. There must be some truth to Sam's changing personality, since John Dykstra jumped ship to freaking Hot Wheels, lolz. Which is probably why the effects in S-M3 arent looking so hot.