My Samsung LNT4665FS's sound shuts off. I have the sound output to a stero receiver. I can watch an hour show and most of the time will have to cyle the TV's power 2 or 3 times. I have tried 2 other stereo receivers with the same result. This happens on the electrical audio outputs as well as the optical. I am unable to change sound back to the TV's speakers as the "Sound Select" option in the menu is greyed out. Any help is appreciated.