It's not 100% of the time. I tried all 4 controllers of mine. As well as two of my friends consoles. Every single controller and console had the issue. Yes this is 360.
Dunno then. I've had controllers have drift out of the box new, but if you're getting it on multiple controllers and consoles that's probably not it. I wasn't getting it, but I only did it for like a minute. Weird that they wouldn't even acknowledge it on their forums though.