Have you tried the new drivers, 1.0-9755?
They work like a charm on my home system,
680i, 8800GTX, etc, etc on opensuse 10.2 x64.
Very stable though the gfx cards do get a tad hot,
but i think thats normal for 8800.
Link:Nvidia x64 driver page
edit: Didn't notice that you already tried those, oopsa...