Hello from Russia and sorry for my bad English. I have almost the same problem on my laptop under Debian etch or lenny. I've installed my system without any graphics support (xserver kde or gnome) it was etch. After that I've installed kernel + xorg + kde from lenny's standart packages and updated other packages to lenny's packages. So my kde only can show panel without any icons and clean desktop after 15-20 minutes of loading and that's all. Logs shows nothing, system works fine at all - no overuse of any resources.
P.S. I also have an nVidia card and chipset on my lap (GeForce 7000M and nForce 610 (do not remember exactly)). So if people have any experiense about this trouble, I'll be glad to find a descision -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]