Found drivers for XP 64bit and Vista 32/64bit its a beta driver but it looks legit to me. The Vista driver will also work with Windows 7. I am guessing due to the age of the card it was never updated for anything but Windows XP 32bit.
What OS you running I will look around some more and see what I can dig up..
(Edit) LOL Forgot link.http://www.driversdown.com/drivers/20526.shtml