Problem with Surround Sound Attached to My Tv?

i purchased a sony bravia 40" lcd tv and i plugged a optical cable from the tv to my SAMSUNG 5.1 surround it works most of the time but quite frequently the sounds goes for a like a second and sometimes if my surround sound is on standby it just switches it selfs on does anyone know whats causing these problems?

Suggestion:

Disconnect the digital cable and connect an a/v cable and see if you have the same problem. If you don't then the digital cable is bad

Why is your s/s on standby? Confused