I've got Time Warner cable and the Scientific Atlanta 3100HD cable box running through a Toshiba 50H81. While watching HBO-HD, the picture looks terrific but every once in a while it'll give a little jerk as if we just skipped a frame. No sound dropout, just a picture glitch. Has anyone else experienced this? Could it be a setting in my Tosh that I need to change for the HDTV feed from the cable box?