Did you re-install Mandrake? Presuming that you did, during the install you should have had the opportunity to test your X configuration prior to finishing. Did you test it?
I think I recall that you have the option of doing an "expert" install or a more automated install with Mandrake. If you didn't choose the "expert" install, then you may not get the chance to test the X configuration. Maybe that is what the problem is? Try it again with the expert option (don't worry, its not too bad) and you will have more control over what is installed. One other thing, when it comes to package installation, just let it do its thing. If you get too weird with selecting packages, you'll be off into dependency he_ _.
I did a quick check of the Video HowTo (
http://www.tldp.org/HOWTO/Hardware-HOWTO/video.html) and did not see this card listed as being Linux compatible. That doesn't mean it won't work. It just may require some rather intense fiddling to accomplish this.
You could also try another path. I would try Knoppix first. Knoppix is a complete Debian based (thats a real good thing) Linux distro that is designed to run from a CD. You can download the ISO image from here:
http://www.knoppix.org/ and then burn the image to CD. They have some good instructions there to help you too. If you made the CD correclty, and your PC is capable of booting from the CD drive, you simply insert your shiny new CD into the drive and let it boot. At the Knoppix boot prompt, enter : Knoppix lang=us and off you go. If you're video card is Linux compatible at all, Knoppix will detect it automatically and you will be presented with a KDE desktop. If this doesn't work, get a new video card.
