I had similar issues a few years ago. I use my SBT to stream from my Vortexbox (Linux-based) server. Try going to the GUI on a networked computer in your home, by entering the IP address for the SBT. Once there, open the Logitec server page and look for a dropdown box labeled "player". You should see your SBT as a choice there. Select it. You may need to reboot your SBT and/or your iMac, too.