Weird sound problem on PVR-150MCE

[Tiger11]

I use PVR-150MCE (No FM tuner version) and use the standard TV tuner to record channels. The video is flawless, however the audio, on SOME channels, seems jerky sometimes, I futher looked in the problem, and I noticed that those channels seem to broadcast at a higher volume, and whent the volume reaches up to a certain level, the card 'mutes it' momentarily. It records this way too. It is obvious when watching a sitcom when the audience laugh, but barely noticeable during the normal dialog.

ANyone faced this problem? Could it be a driver issue?