What do I need for DTS HD output? I have a relatively new receiver and five speakers. Specifically, we have this.

I have the HDMI input for the blu-ray player plugged directly into the tv, and then the tv is connected to our receiver via an optical cable. I don't see why it wouldn't work under these circumstances, but it doesn't. The speakers are all very old, but the receiver is practically brand new. Any ideas? All I want is my damn Apocalypse Now... if this helps, this is our blu-ray player. If someone could help you'd be y hero for the day.