err its nothing to do with the cpu, infact my cpu would be more picky since the memory controlers are inbuilt....
if you mix p2100 and pc 3200 you need to run it at pc2100 speeds
simple really.
for me i have 512mb PC2700, and 2x256mb PC3200, so i had to drop my speed to Pc2700, it makes some games slower, and some faster because some games need loads of ram, others need fast ram..... Alt tabbing is also much faster with 1 gig.