I'm was able to play ATSC fine, but Colossus always crashes with playing live TV (And I also get no sound, but when playing a recording in WMP it plays fine).
Not that it helps you any, but I'm having the exact same problem. LiveTV always crashes. If I can pause it before it crashes, once I unpause it is ok. I have scheduled a recording of a half hour program and it plays back fine in it's entirety. I've got a Colossus and I'm playing back HDMI through a Radeon HD4250 which is part of the motherboard. What type of video card do you have?