Need help with my Onkyo 507!

[gymclothes412]

I bought the Onkyo 507 a couple weeks ago and I've run into a problem. I have my cable box/DVR connected to my receiver via HDMI and noticed that some of the HD channels come in with audio from only my front left and right speakers and subwoofer and some channels come in with audio from all speakers in Dolby Digital sound. If I connect the cable box/DVR to my receiver via digital optical cable, I get audio from all speakers in Dolby Digital sound. What am I doing wrong in my HDMI connection?

I'm also having trouble getting video from my TV when I play a Blu-Ray disc. I have audio, but no picture. I have the BD player connected to my receiver via HDMI and from the receiver to my TV via HDMI with a HDMI/DVI adapter on the TV. Before I got my Onkyo 507, I had an Onkyo 502 and connected my BD player directly to my TV via HDMI/DVI for picture and a digital optical cable from my BD player to my receiver for audio and it worked fine. Again, what am I doing wrong?

Thanks in advance for any help!


My setup:
TV: Sony WEGA 51" KP-51WS500
Receiver: Onkyo TX-SR507
Comcast HD Cable/DVR Explorer 8300HD
BD Player: Samsung BD-P1500
Speakers: Polk RM6200
Subwoofer: Polk PSW250