Youre right, seems there is a directory there, which is not supposed to be there. Directories are a typical devfs-thing but the nvidia-driver does not support devfs, AFAIK, does it the old style...
So, you could try to delete the nvidia*-stuff in /lib/dev-state, I guess it's being backupped from there on demand by devfsd or something like that.
Permissions look fine, you need to rw- as user to run glx-things in X. To hinder msec from overriding perms there I have the following set in perm.local:
[root@blackbox root]# cat /etc/security/msec/perm.local
/dev/nvidia0 root.games 4660
/dev/nvidiactl root.games 4660
where games is a group \me lives in. "current" would tell it not to touch these things, if I remember right. I do not exactly remember what the magic 4660 mean, but... works.
/dev/nvidia* looks like this here:
$ ll /dev/nvidia*
crw-rw---- 1 root games 195, 0 Dez 19 2003 /dev/nvidia0
crw-rw---- 1 root games 195, 255 Dez 19 2003 /dev/nvidiactl
1970 dates are a trace to devfs, it's the beginning of time on Unix-Systems, devfs|d will set this date on dev-nodes it creates dynamically.
goodLuck, have a nice Xmas!