Several channels and/or broadcasts - notably, TSN broadcast of the Sharks/Kings game this evening, and Cesar Millan's Leader of the Pack on National Geographic Wild - only have dialog audible if DVS is turned on. Background music/sound IS audible at all times - it is only the dialog that is not audible without DVS being engaged. Note that TSN did NOT have this problem on the pre-game or other programs - it only showed up for the hockey game.
And, of course, turning DVS on turns OFF the dialog on all the other channels.
This is happening with a current-gen HDPVR.