The sound fluctuations that I'm noticing are small enough that I'm not even sure I'd notice them if I wasn't 1) listening for them and 2) wearing headphones. I'm betting a lot of the people who are saying there's nothing wrong just haven't observed it yet.
At least on mine, the uneven sound only seems to happen during songs, not during the dialogue portions. Anyone else notice this?
"A little humility wouldn't hurt."
--Ellie, Constantine-Hellblazer, "Dangerous Habits"