I have problems with divx too, but when i exchanged
the heatsink of my PPC to a more BIG one, bang, play fine

, well here i used to have 25 C to 35 C, so the temperature in my PPC is a BIG issue., my PPC is overclocked now the default Mhz in my card is 210, of course i overclocked the 68k (040/33Mhz) too and the BUS memory :-D 66Mhz, and i will try a little far with the CPU like 266Mhz to be close or equal to your PPC.