One thing I've noticed about the ring of light around the power button is how the segment for each connected controller persists, despite the orientation of the unit (for example, player 1 will always be the top-left segment).

I keep my 360 vertical, and while I'm not foolish enough to move the thing while it's on, recently the lit segment occasionally changes to the expected position as if the unit was horizontal, then changes back when it pleases. No other controllers are active while this is happening. The batteries in my controller are fresh, and there are none of the telltale symptoms of desynching while playing.

Am I right to be worried?

Are you on Planet Earth?
Gravity seems strange in your area!

I think your house is doing backflips.

OMG ITS A SIGN OF RROD!! OMG OMG!!!! BE AFRAID BE VERY AFRAID!!!!!.
(Had to get in before the Sony Fanboys did)

I have never heard of this happening, that makes your 360 unique, i think it would be funny and you neednt worry.

A glitch in the Matrix?

i think your on to something...