New video card has AIDS

I just got my new 6800 AGP video card today.  I bought it off newegg.com.  It's this one right here
http://www.newegg.com/Product/Product.asp?Item=N82E16814121216

I installed the drivers at first from nVidia's website and it works...just not on games.  In games, everything flickers and some of the text on menus is gone to the point where they're completely unplayable.  Then I tried the CD that came with the card, but that just gets my comp stuck in 4 bit color.  Really frustrating.

Anybody have any ideas as to what this cold be?  Is it my MoBo or could the card be defective?  I really don't want to have to return it to newegg.

Yes its definately the motherboard that you didnt state the name or mnodel of thats at fault.

I suggest you recompile your kernel entirely so fully support nVidia drivers, edit your lilo or grub to boot to it and download any required modules.
Failing that remove the card from your mac.

God i love support threads where they dont actualy specify details like OS, motherboards or supply any kind of logs.