Sorry, I had no reference system. You are right.
I have almost the same xorg.conf file. (almost same monitor, nvidia GeForce 6800) Differences are in the Files section:
# Multiple FontPath entries are allowed (they are concatenated together)
# By default, a font server independent of the X server is
# used to render fonts.
I think you have checked the path already?!
Please compare. I have
yum list installed | grep nvidia
Before I have tried to use the other packages and had also some problems. As longer as I think about eveything, that must be your problem...
Try this first!
Hope you succeed!