[V4L] /dev/video0 ownership flags change by themselves...

Hi,

On my RedHat 6.2 linux PC, /dev/video0 ownership flags change each time
I log in/out an X session (I use gnome's gdm). I need to stop this
behavior and have 'fixed' ownership flags on /dev/video0.

This change in ownership flags is a problem for me because I try to
access to the video card from a PHP script that runs as 'nobody'. As a
temporary fix, I 'chown' manually each time I start an X session. 

In the long term, I would rather stop the unexpected change of ownership
flags each time I log in/out and I would rather have fixed flags. Any
idea on how to do that?

In more details:

--- I log in (X session) as user fdumas; then:
> su 
# ls -l /dev/video0
       crw-------    1 fdumas root      81,  /dev/video0
# chmod 666 /dev/video1
# ls -l /dev/video0    
       crw-rw-rw-    1 fdumas root      81,  /dev/video0

--- I log out from my X session and log in again, then:
# ls -l /dev/video0
       crw-------    1 fdumas root      81,  /dev/video0

--- I log out from my X session again and log in as user alcouffe:
# ls -l /dev/video0
       crw-------    1 alcouffe root    81,  /dev/video0

I can't find what is doing that. I assume this is done for security
reasons. I have tried to remove gdm's PreSession and PostSession scripts
without any change. 

Thanks for any help,
Frederic Dumas