TsMuxer works for me, but not frame accurately.
 

I am using TsMuxerGUI 1.10.6, it joins my .ts files from Hauppauge HD PVR correctly.

The only shortcoming is that its editing function is not Frame Accurate. But it surely does not re-encode any thing, so the video quality is maintained well.

But when I want to cut out commercials I want frame accuracy, I would like to use Smart Cutter for Dv and DVB from FameRing, which is Frame Accurate, and supports 'smart rendering'. It only re-encode the gop on cut point and end point, leaving middle part of movie untouched. Speed and quality are both achieved.

But Smart Cutter is not free, I wish someday TsMuxerGUI can release a frame accurate version. That will be nice.