VNC cannot access sound card without local login on Linux

[Timothy J. Massey]

Hello!

I am relatively new to VNC on Linux, though I have been using it for 
some time on Windows.  I'm building a MP3 player in a Mini-ITX computer 
for my living room.  It uses Linux and VNC to run XMMS and play MP3's 
through the host's sound card.  This works, but only if the VNC user is 
*also* logged into the computer locally.

Why is this?  Why can't a VNC user access the sound card without having 
the same user logged in locally?

In other words, I have a user called xmms.  I have a vncserver run on 
startup as that user.  If I remotely start XMMS using VNC, it will start 
but it will not play:  it tells me that it cannot open the sound card.  
However, if I then log in locally as xmms (even just into a text 
console), I can then access the sound card from within VNC.  If I am 
playing an MP3 via VNC and log out the local xmms user, the MP3 will 
continue to play.  However, if I stop the MP3 and restart, I get the 
same error message.

I have tested this on Redhat 9 and Fedora Core 1:  same results.  I've 
worked around this by having the computer automatically log in the xmms 
user on boot, but that's obviously ugly.  I'm guessing it has more to do 
with running XMMS on display 1 instead of 0 than VNC proper, but that's 
a total guess.  I'm sorry if this is a FAQ, but I've tried to search for 
answers, but I can't find anything even *close*.

Thank you very much for any help you might be able to give me.

Tim Massey