I have a problem wsith getting my nvidia card working & i have mostly the same specs as u
AMD Athlon 2600+

1GB PC3200 Mem
Nvidia GeForce 5700 Vid Card with 256mb onboard memory
Sound Blaster Audigy 2 ZS platinum pro

I dont think that thesound card has anything to do with it LOL

your problem seems to be that, like windows, knoppix systems may not like nvidia, because nvidia failed to pay mr knopper billions of dollars to support its hardware. LOL