The only time this happened to me was when I had my set top box set to output the native channel resolution. If a channel is 720p you'll get 720p out, if its 1080i you'll get 1080i out. The TV has to sync up every time. Also, you'll get a screwed up picture if your box sends out 480i (via DVI)
I now leave mine at 1080i since most HD channels are 1080i (I'll manually switch it 720p if I'm watching Fox, ABC, or ESPN).
Hope this helps!
I now leave mine at 1080i since most HD channels are 1080i (I'll manually switch it 720p if I'm watching Fox, ABC, or ESPN).
Hope this helps!