I recently upgraded to the HR21-100 DVR. When we used the HDMI cable, everything looks fine with the picture. But when you turn the channel, there is a loud crackling sound. Almost like a snapping sound. When I use the Component cables, the strange sound is gone. Has anyone had this issue? I never had the problem before with my old Mpeg2 HD-DVR. I would really like to use HDMI.