This is unbelivable. I tried another aproach, this time i installed the drivers from the non-free official repos. I configured the card with XFdrake, cause that's what it said in the download notes, and now i have 3d accel, but i can't set a resolution higher than 1024x768. Any ideea on why kde is not starting?? :-s...thanks.
Edit: Well, i'm stuck with gnome and a 1024x768 @ 70Hz resolution for now. Can't fix kde. If anyone has any ideea on this...