Ok not sure here but SX with 256 Mb... that's like the bare minimum.. In chance on trying with a "bigger machine"?

Sounds like yer video card is absolutly baffled with all the screening (thoug I'm going on a limb here 'cause I don't really know much about PC/ Macs).... maybe yer video card is sucking proc. from yer ram, leaving it under the water line!!

Just another though... try sending all yer files 2 *.wav format just out of curiousity 2 C how that matches up.... should make a difference... but there is no harm in trying!!

Z