I recently upgraded from a Motorola dual DVR DVI output cable box to dual DVR HDMI Motorola box through Comcast Cable because of clitches with the DVI box. The remaining serious problem with the DVI box was an audio muting problem which I now find out is common even with the new boxes...seems everyone knew about it except Comcast customer service, which now has a programming fix. The new box is a Motorola DCT 6412-2305 with an HDMI out in place of the DVI out. The main problem with this is when I play back a program recorded in Dolby 5.1 and the TV input is set to HDMI the Dolby 5.1 to my Yamaha reciever does not work (the DVI box worked fine even when two programs were recorded at the same time). Comcast could not figure why this was not working. Recently Comcast Techs were at my house trying to remedy the problem without success. While here, they received a call from anoter tech with the same problem. After they left, I discovered that if I set my TV to component input, the Dobly 5.1 works fine. A co-worker of mine feels since HDMI is a 2-way path that some sort of copy protection my be interfering with the Dolby signal. I called Motorola Tech services...they deferred the problem back to Comcast. Anyone experienced this...have a fix???