Root and xmms / realplay9

Have what I think is a permissions problem, but I'm not sure.

I have a central server and thin client terminals. I wish to run xmms
and realplay9 on the server, using esound (which is rather like X11) to
send the sound over the network to an esound server running on the thin
client device.

When I am root on the server, it works.

When I am not, it doesn't work. I have tried chmod +s the binaries,
and using sudo. Neither worked.

I wondered whether this was something to do with the program trying to
get access to a communication port, but I don't know.
ANy suggestions much appreciated.

regards

Jon