TiVodecode is an unauthorised hack and has not been developed for a few years now. It does seem to have some problem decoding TS at times, but I find it is ok with PS.

All free tools use tivodecode, so there is not any other free option.

There is a another paid option which many people swear by called videoredo studio, you can download a free trial to see if you like it.

If you use KMTTG, and only select decode (not encode) does the resulting file run ok? If it does, then it is the encoding that is inducing an error, you may want to try a different encoding profile to see what works for you.

As for TiVoDesktop, it should work for you. But you did have a very low signal strength, and still a little low which might upset it. I just don't like using it because it is flakey and a resource hog.

Peter.