I have 2 Mac laptops and 2 PC desktops all connected to a airport extreme (802.11g version) with 2 airport express boxes in a WDS network. The Macs have speaker selections and can share libraries in ITunes. The 2 PC's are connected in a wired network to each other and then connected to the network by ethernet to a airport express. The 2 PC's can share ITunes library but do not show speaker location or share libraries with the Macs. I would appreciate any info on how to solve this. Ethernet is enabled on both airport express boxes>