I recently purchased a Sony XBR75X900e and a Sony AVR STR-DN1080. I have connected a DIRECTV HR44-700, Sony BlueRay and Apple TV to the Sony AVR. Here is my setup:
Ethernet from Router to Directv HR44-700
Cat5 from splitter to Directv HR44-700
Directv HDMI out to Sony AVR SAT/CATV HDMI...