You could try:
16 bit colour
aa and af off
lower refresh (say 75 Hz or slightly faster as minimum)
disabling enhanced cpu instructions in opengl
lower ram timings
setting fast cpu decode to off
trying a different driver
trying the game in question at bios and vid card defaults, just to check.
just some thoughts
via could not pay me to install any 4n1s other than those that are in xp or 2k natively...