Unibrain extender did not work for me.
However Newnex FireNex CAT5 repeaters work very nicely interconnecting bedroom/living with 75ft Cat6 cable. I stream HDTV from my Comcast DVR to the bedroom Mac Pro. Devices are connected to Kramer powered hubs-computers, tuners, disc subunits, dvr's, tv's.
My Yamaha DVD-S2500 is flaky though. When powered off, my Sharp tv drops out of the network. While powered on all nodes function properly. All nodes connected to a hub with Firenex repeater connecting rooms.