Struggling to get DTS HD MA to output via HDMI from Panasonic DMR BS750 blu Ray. It's connected to Sony STRDN 1000 receiver. It outputs 5.1 sound fine but on DTS HD 7.1 (little mermaid blu ray) it outputs only in 2 channel not surround. My speaker set up is 5.1 so thought it would be able to handle this. From reading the manuals both units can handle DTS HD. Any pointers would be much appreciated