Same problem for me. Saw it for a few days a couple of month ago than it came back to normal (Only SD Channel). The TV didn't make a difference. I saw it first on my 42" Plasma than when it came back 2 weeks ago, I tried also on my 27" and 13" and still saw it. Tried 4 different connections (RCA, S-Video, Component and HDMI) and the problem was still there. Then I called a Videotron Tech that came to change it. Same problem is back a few hours later. Will probably call them soon again to change it. They have no idea what could be causing this problem. I'll keep you informed.