We have recently purchased a DCX3400 PVR, and although it works really fine, sometimes we lose the sound on all channels including that which is recorded. Or the TV will work fine but the recorded shows will not. Or sometimes, the only channel we can hear is the one that comes on when we turn on the TV. The only way to get it back is to either shut the TV off for a few seconds, or unplug and replug the HDMI cord. Could this be the result of a faulty cord, or something in the PVR itself? Has anyone else ever had this problem?