I noticed when NOT in smart sound mode, there's a noticeable "skip" in the sound about every 15 or 30 minutes. Not sure if this happens every time the TV is on, but I do notice it sometimes. I have a Panasonic HDTV connected to the soundbar with the optical cable.
When I get the sound skip issue, the display briefly switches from "DIGI 1" to "PCM" before switching back.
Relatedly, I think, are definite sound volume jumps when the smart sound is turned on - when not going to commercial. It's really annoying - so much so, that after 30 minutes, I turn off smart sound. For example, I'll be watching the news, and the announcers voice will suddenly drop down a notch. Not completely, but enough to notice.
Anybody have these issues?
-> UPDATE: I hooked up the optical cable directly from the DirecTV box to the soundbar and this - so far - has solves the issue.