@darnweight wrote:
NSLU2 is connected via ethernet to a Belkin Wireless G ADSL Modem/Router. PC and Soundbridge access is Wireless.
And here lies your problem.
You need to adjust the router settings to allow multicast packets to pass between the wired & wireless networks.
iTunes & the SB find servers via multicast packets, your router is preventing the packets from the NSLU2 reaching the SB / iTunes.