Hi RJRon,
silly question... but.... is the XBOX on the same network has your DNS-323?
In the DNS-323... the "Media" folder you created, is that the one shared, or is the "Root" shared?
ie. if its the "Media" folder that is shared, it should say something like "Volume_1\Media" in the DNS-323
try by putting only 1 MP3 in that folder, and give it a simple name like "TEST.MP3"
Click on the REFRESH button in the DNS-323 UPnP Page
Turn on you XBOX and then go to "Music Library"... your DNS should show up...
if not, try the following
disable UPnP
reboot DNS-323
enable UPnP - share the Media folder in UPnP
it should now show in the Xbox... if still not try doing a reset to Defaults of the DNS-323