It does sound like a driver problem. Where are you getting yours from? The regular desktop drivers should not be used in laptops, if they work at all, there will still be problems galore. I have had some success in the past with modded notebook drivers, omega used to put some out, but doesn't anymore, though you may be able to get an old driver there. The good news is that nVidia finally started releasing drivers for their mobile gpu's. Use the link in this news page.
http://www.notebookreview.com/default.asp?newsID=4742
On the temperature issue, have you checked the bios and/or installed any monitoring software to see what they are? Do a search for NHC, it's pretty good. Full name is Notebook Hardware Control, I'd put in a link, but I'm at work so have to limit my internet usage somewhat.