I have used MC for awhile and have never had issues until last year around October. When watching local channel 11, I noticed that there was no sound, the main sound. I here all the back ground sounds, just not the talking sounds. Later, channel 4 starting having the same issues. At this time, all other channels are sounding perfect (ch 5,8,13,21...etc). Playing MP3 files, there is no sound problems.
This started with MC 18, now I am using MC 20 and still have the same problem. Using a twin tuner, Hauppauge WinTV-7164; that I have been using since late 2013. Thank you - Norman