If you’ve installed the stable version i.e. 0.2.4.1-1 then it’s daap only I’m afraid.
UPnP clients will not see the server.
Nightlies versions use daap & rsp but UPnP is still not fully implemented
As for the the songs not appearing in iTunes. Which port is your hard drive connected to?
If it’s connected to USB port 2 on the NSLU2 then you have to change the path to /share/flash/data/public/mp3