First let me say you have a great forum here and I tried to search for an exisiting answer but probably have over looked it. Received a call from TWC on Saturday 01/30/2010 that on Tuesday 02/02/2010 my boxes would no longer work. Went today and picked up 2 new boxes, one is an Explorer 8640HDC and the other is some Samsung unit. The Samsung is not an issue since it is not hooked up to any surround sound. The Explorer 8640HDC seems to be the problem. This unit is connected to a Hitachi 50VF820 via HDMI to the TV and then the audio is connecting via Coax to an Onyko HT-R530. I went into the setup in the Explorer 8640HDC and set the audio output to Dolby digital and then made sure on the Onyko that the digital input was set to Coax. There are other components connected to this system but they are not part of the issue since nothing is connected from the Explorer 8640HDC to them. The display on the Onyko says Dolby D and I get sound from the front left and right channels and the center channel but nothing out of the mid or rears. Also the indicator on my sub woofer is showing red instead of green indicating a signal is not being sent. Tonight watching 24 on FOX it really sucked that this is the only sound I received. I can change some settings on the Onyko HT-530 to simulate different surround sound but that is not what I want. My old DVR box from TWC had no issues like this. When I switched to a Dolby D signal station it played correctly and when commercials came on that were not recorded in Dolby D it switched to the correct signal Stereo. When 24 ended and the local news came on the Onyko switched to Stereo like normal. Also switching channels my Onyko would have a click noise when it changed from different signal types but this new box I don’t get this pause and click. I also know that nothing was disconnected during the change out. All that I had to disconnect was the Coax for the sound, HDMI for the TV, Coax for the cable and the power cable. As a side note they had me use my old power cables, wish they told people this up front it would have been a lot easier changing out since this was the cable that gave me the most trouble. I know I have it hooked up correctly on the back of the box there is a Coax output and that’s where I have it connected. To confirm that it wasn’t an issue with my Onyko or something without me noticing came lose I played a Pink Floyd DVD in my PS3 and it shows Dolby D and sound was played from all channels, front, mid, rear subwoofer and center. Now where do I start trouble shooting? Logically since the DVR was changed out this is where I think I need to start. I have noticed as I was scrolling through TV stations that I did on occasion have a station that produced a Dolby D signal and all channels played. This would lead me to think that it was FOX and not TWC or the Explorer 8640HDC but having sound from front left and right channels and center channels makes think it is another issue. Why would a station only produce sounds out of these channels? I do have an HDMI Switch it isn’t part of the equation but I am wondering if I should as a test connect the HDMI and audio signal from the Explorer 8640HDC to the Atlona AT-HD41D switch and then send that signal to the TV and head unit. Seems like this might be a possible signal loss having more connections that necessary. Time to ask the experts, help guys have a lot of money invested and nothing to show for it since this change out. Below is a link to a picture of the set top box rear view and how I have things connected: 'http://www.homeofstewarts.net/image2.jpg'