Were you using a Voodoo2 or 3 previously. If so you may not have
completely uninstalled it's drivers. If not, I believe that the
drivers for the Voodoo5 are still evolving. Check for the latest ones
at their site. It may also have something to do with the settings you
are using for the card.
I don't have that card myself, but there maybe something in your
default settings for it that need to be modified. Every account I've
read is that it's a wonderful card for GPL even though the full-screen
anti-aliasing does result in a frame-rate hit. Someone here should be
able to compare settings with you to get it sorted out.
Regards,
Brett C. Cammack
That's Racing! Motorsports
Pompano Beach, FL