Try watching a HD channel for more than 5 minutes. It is constantly pixelated, and every few minutes kicks you back to the guide. The issue has been going on for several months and there are numerous posts about it. I was watching a sporting event yesterday and it kicked me back to the guide every 4-5 minutes. I've tried to watch AMC on Sunday at 5:00AM EST and it was doing the same thing. There is a problem and it doesn't seem like it is being addressed. Maybe it is and I'm not aware of it, but this has been going on for months without any improvement.
I am not disagreeing with you.
Although not all HD channels are doing this, some are okay and have improved.
And this has been reported to service administration (again).
Maybe we can get an update on what to expect, but do not hold your breath on that.