I'm using a HTPC to drive a Panny AE-700U via HDMI. The picture is incredible, simply stunning. Way beyond my expectations. The problem I have is I can't get any center channel information from my HT receiver. Audio connection is made from the PC to the headunit via Belden 1694A out of the SPDIF. It is fed to a Yamaha 5790 used for pre/pro. The Yamaha has all 5.1 channels lit in the display. This means that it is getting a 5.1 signal. However when I engage DDEX, DPLIIx, or any other digital surround decoder setting I am without information from the center. I know that the center channel is connected to the receiver because when the video source is switched on the yammy to HDTV (cable) I get center playback from HD channels. I am using ZoomPlayer Pro and FFDShow for PP. I don't think the problem is software related, however. I used Windows Media Player 10 to view the testing movie (The Day After Tomorrow) with the same results from the center. I have confirmed that the AC3 chip is engaged in BIOS. I know it is because before any media player is engaged in the Windows environment my receiver indicates it's getting a 5.1 signal from the PC. For some reason the full 5.1 channel information simply isn't being sent over the connection. Any ideas? I have to watch movies from an unscaled, traditional DVD player until I get this resolved because at least it does have the full 5.1 sound information. But it sucks because it doesn't hold a candle to the video from my HTPC resized to 1776/1000 and projected on a big screen. Nice colors from the outboard DVD but artifacts are there if you look for them. If it matters, I'm using Win XP, Athlon 2800, 1 GB Corsair XMS, NVidia 5900XT. Sound is on board from a NFI Lanparty II Ultra B. Thanks for any and all suggestions.