If the extension is .ts then what you're getting saved is the Transport Stream, which bundles together the video, different sound channels, subtitles and so on together.
If HDTV Pump I linked to before doesn't work, the alternative if you want to view the video on say your laptop is to strip all the component parts out - called Demuxing - and then combine them back and export in a standard video file format.
It's not as complicated as it sounds and some programs will do the demux in the background anyway so you don't need to worry about it.
Try
MPEG Streamclip which is a freebie but pretty easy to use.
Or if you don't mind paying £
Womble DVD Wizard which also is good at editing the video, adding fades and cutouts, that sort of thing. Or
Videoredo which is similar.
There are some other free alternatives if those don't work, but they can be tricky to use.