I recently acquired a 2-3 year old PDP-4340HD Plasma w/the media center box. I wired it to Comcast cable via component cables but there is a bit of audio hum so I changed to HDMI cable. Cured most of the hum but created a new problem. When I switch from HD to non-HD cable channels, the system freezes. I have to turn the cable box and TV off and then it will accept either channels. Does not matter if going from HD to non-HD or vice, versa. (it works fine with the composite cables)

I had the cable guy out and he said it was because the media box connected to the plasma screen via DVI cable and that the DVI connection was too slow to take the HDMI signal (or something like that.) I have no way to work around the DVI connection so I'm looking for ideas how make use of the HDMI cable connection primarily just to rid myself of the hum but so that I can change channels like a normal person.

Thanks.

JB