Windows Media Player can decode VBR MP3 streams as generated by the Instreamer or the older Instreamer100, but in recent versions it does not calculate the buffering correctly. This is *not* a problem on the Barix side, it has been proven to be a problem with WMP. There is a simple workaround: when WMP starts with "buffering", press the play button a second time and the stream will start playing. On the newer Barix Instreamer you can also setup the MPEG Bitrate Mode = CBR, this works better with Windows Media player.