Also having this problem with Linkstation Pro. Sees the library but the music won't play. Will happily play when itunes is pointing at the Linkstation, just not when it's being used as the iTunes server in the shared section of iTunes.
I'm using Linkstation Pro LS-XHL211
Firmware 1.10
ITunes 9 on Mac OS 10.4.11 also on Vista
Have tried restarting media server to no avail.
Hope someone can help, as this was the main reason for buying this drive.
Thanks.