Probably a bug in the video driver.
Unfortunately, there
don't seem to be any 3-D Studio Max certified drivers for any Intel GMA integrated video controllers (
the G41 uses the GMA X4500). (
More information.)
Do you have $2 500 lying around to add cheap (certified) video cards to all of the computers? If not, you may just have to employ trial and error to see if any older or newer revisions of the drivers work better for you.