I had this problem too. If I'm not mistaken, what I did was edit the
/etc/udev/permissions.d/udev.permissions
file... Go down to the "dri devices" section... mine looks like this:
Code:
# dri devices
nvidia*:root:video:0666
3dfx*:root:video:0660
dri/*:root:video:0660
Notice the "0666" after nvidia*. As far as I can remember, that's what you have to change for it work. (the default is 0660 I think).
-- Hernán