Hups. I'll have to look and see where I missed to find the
information in the man-pages ;-)

The following now workes as expacted. In addition I only
needed to do a chmod 666 /dev/rsd0*  and /dev/rcd0*
in order to eject the media as an ordinary user.


# /etc/amd/media
#
cd              dev:=/dev/cd0a;type:=cdfs;opts:=ro,nosuid,nodev
sd              dev:=/dev/sd0a;type:=pcfs;opts:=rw,nosuid,nodev