I have been experiencing problems on and off getting any user to mount 
stuff.  Bottom line is this:  Add "user" (not "users") to /dev/cdrom in 
/etc/fstab to get it working.  If it still bugs out or gives you errors, 
re-emerge util-linux or shadow or pam for permissions reset/fixes.  So 
far, that's always worked.

Supermount seems to patch okay on 2.6.6.  It complained that it couldnt 
patch some SCSI driver, but who cares.

Here's how to patch the kernel:

gzcat supermount-2.0.3-2.6.0.patch.gz | patch -p1 

The flag is in:

File systems  --->
    Pseudo filesystems  --->
        <*> Supermount removable media support 

add these changes to /etc/fstab:

none	/mnt/dvd	supermount      fs=auto,dev=/dev/cdroms/cdrom1  0 0

none                    /mnt/cdrw       supermount      
fs=auto,dev=/dev/cdroms/cdrom0  0 0