I think you'll find that totem and xine will try to mount/use the device as the user.
This wont work unless the user is either the owner or a member of the owning group of the device.
eg. in k3b there's an option to use a burning group (eg. cdrom)
my ownership looks like:
$ls -l /dev/dvdrw
lrwxr-xr-x 1 root cdrom 8 Feb 17 15:46 /dev/dvdrw -> /dev/hdc
$ls -l /dev/hdc
brw-rw---- 1 root cdrom 22, 0 Mar 15 2002 /dev/hdc
and the relevant group info:
$cat /etc/group | grep cdrom
cdrom:x:24:user1,user2,user3
I did have a few (test) vcd's lying around at some stage, but I've probably deleted or trashed them by now,
so I'm unable to test if this is really your problem.
ps. I'm also not convinced that my permissions are correct for /dev/dvdrw (ie. world?), but it works,
and I'm lazy