I have always had video glitches with my ASUS V7700 GeForce2 and this Abit board. Have you tried the faq at go.to/kt7faq? They have a great resource about the KT7&KT7-RAID. Can you be more specific about the problems you are having?
I had a similar problem with my KT7 RAID and my Hercules 3D Prophet II GTS Pro 64Mb.
My card worked in another machine, and my Voodoo 3 worked with my KT7.
Turns out the mobo has difficulty supplying the card with enough power, so you get instability. Mine would very rarely get past POST.
1) If you have an early revision of the GF2, speak to your card manufacturer and see if they recognise the problem. (I did this with Guillemot, and they have sent me a brand spanking new card which does work with my KT7!)
2) Make sure your PSU is at least 300W (preferably more!)