blu ray "echo"

I have s Samsung blu ray player ht-c5500

Suddenly, over the weekend, when I output sound to the player via the optical link...there is a Stadium like effect...an echo Particularly with speech...even though audio and video appear to be in sync and changing the delay does not help>>>>

...the right, left and center speakers appear to all be playing the same exact audio.
this occurs when the optical input is directly from the cable box as well.

When a dvd is played in the blu ray sound is normal...

any one else with this problem?
any suggestions???