Re: howto play audio here and hear it there

I'm running Fedora 11 with the gnome desktop on a small LAN. I'd like to
run an audio player (say xmms) on box2 and hear it on box1, which is
directly connected to my stereo.

In the past I would connect to box1 from box2 via ssh and then run xmms
from the command line. Now when I try doing this I get this message:

Couldn't open audio. Please check that
Your soundcard is configured properly
You have the correct output plugin selected
No other program is blocking the soundcard.

I can play audio with problems from box1, so the soundcard must be OK.
I have pulseaudio selected as the output plugin in xmms. (The same
problem occurs with alsa and the other plugins.)
It seems likely, then, that the problem is some other program is running
on box1 that is blocking use of the soundcard.

Two related questions:
(1) Does anyone know what other program this might be (gnome?) and how I
might get around the block?
(2) Isn't this the sort of simple application pulseaudio was designed
for? Shouldn't I be able to run xmms on box2 and use pulseaudio to play
the output on box1? Has anyone been able to do anything like this with
pulseaudio and, if so, what settings did you use and where did you set
them?