Terrible picture and sound on two channels only, ESPN and FX. Rest of channels are fine. Picture gets packaged constantly and audio slips in and out. Watching football i can't see the plays and watching a tv show on FX i can't understand what is going on because of this. It is terrible and the shows don't make sense because parts are unseen or unheard. This has happened 3 weeks in a row but only these two channels. I did a Comcast reset and I also unplugged and restarted. Why are these two channels so bad?