I think it might be a bad nvidia driver. But if you notice anything wrong in the xorg, let me know.
Here's the rpms I have installed
and the search I used)
rpm -qa *nvidia*
kmod-nvidia-1.0.9762-1.2.6.21_1.3194.fc7
xorg-x11-drv-nvidia-1.0.9762-2.lvn7
xorg-x11-drv-nvidia-devel-1.0.9762-2.lvn7
Confusingly enough, kmod-nvidia-1.0.9762-1.2.6.21_1.3194.fc7 is provided by linvna, according to rpm -qi. Who knows why they chose to change their naming scheme for this?
Anyway, I uninstalled and reinstalled the rpms, just in case. Something appears to be wrong with the nvidia driver.
If it helps, here are the glx rpms I have installed: (and the search I used)
rpm -qa *glx*
glx-utils-6.5.2-10.fc7
rss-glx-kde-0.8.1.p-6.fc6
rss-glx-0.8.1.p-6.fc6
glitz-glx-devel-0.5.6-5.fc7
rss-glx-xscreensaver-0.8.1.p-6.fc6
glitz-glx-0.5.6-5.fc7
rss-glx-gnome-screensaver-0.8.1.p-6.fc6