I have my Toshiba SD200E linked to my Sony Home Theatre system via optical cable. A couple of months ago the amp/display stopped displaying the digital signal and will now only play DVD's in stereo - not Dolby Digital. I have tried hooking up another DVD player and the signal was recognised - playing discs in 5.1 mode. It appears that the problem is with my Toshiba SD200E, I have made sure that all the settings are correct. The only thing which offers any clue is that the display screen on the Sony System Amp reads 48.0 hz when a disk is played. Then just my L and R speakers are active. I can still use Pro Logic II to get the surround effect but not the true sound that should be playing. Is this fixable, any advice. I have had the machine over 5 years and I'm reluctant to loose it.