Hi, tonight i changed my samsung LE26R74BD back to TV from HDMI and it switched back to channel 5, the last channel i'd been watching. The picture was moving in a jerky manner and so i switched the tv off for a few seconds then switched it back on. I now cannot change the channel away from channel 5. I can do everything else (put it on av, HDMI, change the volume up and down, change the picture mode and screen size etc) but it remains stuck on channel 5 and i cannot bring up the electronic program guide either. Please does anyone know what has caused this and more importantly how i can fix this?