I just recently had a thread related to this topic:
http://forums.fedoraforum.org/showthread.php?t=201392
However, I'm not sure if you get direct render = YES as root. Maybe try that. "sudo glxinfo | grep direct". If that's the case, my solution should work for you.
My solution was:
1) I switched the modprobe.d/nvidia file to the following to reflect this:
ptions nvidia NVreg_DeviceFileMode=0660 NVreg_DeviceFileUID=0 NVreg_DeviceFileGID=500 NVreg_ModifyDeviceFiles=1
(500 = my group id)
chgrp'd to "users" /dev/nv*
crw------- 1 root users 195, 0 2008-07-31 06:31 /dev/nvidia0
crw------- 1 root users 195, 1 2008-07-31 06:31 /dev/nvidia1
crw------- 1 root users 195, 2 2008-07-31 06:31 /dev/nvidia2
crw------- 1 root users 195, 3 2008-07-31 06:31 /dev/nvidia3
crw------- 1 root users 195, 255 2008-07-31 06:31 /dev/nvidiactl
crw-rw---- 1 root root 10, 144 2008-10-09 10:31 /dev/nvram
Then I rebooted