You know, I was about to post saying that I've never seen this on my 1070 with my gamecube, but then I just realized that I have no video connections running through the 1070 anymore, and I'm just using the TV's inputs. However, there was a time not too long ago where I had a Xbox, PS2, Gamecube, and dvd player all running through the 1070, and I never had this issue then. I was only converting from composite inputs to S-video though, my old tv didn't have component inputs.