RC2 and vfs.usermount

Hello,

I'm trying to enable cd mount for regular user. User is in group operator and 
cd0 (via atapicam) looks like this:
crw-rw-r--  1 root  operator  -   4,  21 25 Dez 21:06:31 2003 cd0

Also sysctl vfs.usermount returns:
vfs.usermount: 1

But when I try to mount the cd I get the following error:
cd9660: /dev/cd0: Operation not permitted

I absolutely don't understand why. It doesn't matter whether I use the 
atapicam cd0 or the acd0.
What am I missing?

-Harry