I have a SCSI CD-ROM as the only CD-ROM player in the machine. I am using xfmedia compiled from source (Xorg 6.9, xine_lib 1.1.6, XFCE4.4.1) on kernel 2.6.16.49 (UP). When attempting to use the CD-ROM xfmedia seems to fight a process that has the line "hald-addon-storage: polling /dev/sr0" that shows in ps and it shows on top. When adding CD-ROM tracks to the playlist it takes about 20 seconds per song and the xfmedia UI freezes for that time. When playing, you get a few seconds of music and then nothing, then the ui jerks a bit and you get music again. Top shows a war between HAL and xfmedia. This is with HAL 0.5.8.1 and DBUS 1.0.2. It seems xfmedia didn't tell HAL to leave the cd-rom drive alone while xfmedia is using it.
xfmedia doesn't talk to or use HAL at all, so it has nothing to tell it. Can you reproduce this using xine-ui or another xine-lib based frontend? I don't think this is xfmedia's problem; I'm not going to look at it unless it's not reproducible with other xine-based frontends.
Xfmedia is unmaintained.