unfortunately I don't have a solution for your problem. But I'm such a poor samsung x10 owner, too. So, perhaps I can support you here with my voice ;-)
I have exactly the same problems like you. It's quite funny (not real), that I've bought this laptop because there is a nvidia card in it and I thought, there shouldn't be to much problems, installing a driver and having good 3d-support an the laptop, beside any other graphic cards vendor.
At the moment I'm using my laptop with the xfree-nv driver. It's enough for developing, but for gaming I would like to have more fps. ;-)
Hopefully there will be a solution soon, the rest of my laptop works very well (except the wlan, of course)