You do not want 'dri' loaded.
Reportedly agpgart is still pretty broken on 2.6. I see no difference in performance between nvagp and agpgart on my machine, while on any of the 2.6 test / release builds I've done, but its worth the try. (I sound like a broken record if people are reading lots of my posts today, /me chants.. NvAGP!)
Try this Option:
Option "NvAGP" "1"
# Insert Clocks lines here if appropriate
And I suggest removing the second 'Device' definition if its unused in your config.
"..the triumph of evil is for good men to do nothing."
VIDIA video driver RPMs for Fedora
:: see yum repo at livna.org