I'm not really sure how long it's been there. It only shows up when there's a second monitor, and I've not been using one.

It's unfortunately on a deployment image (I thought) I just finished.

My thought is that it was likely to be a video driver thing, too, but I can't find any option anywhere in the video driver config screens. It's an Intel GMA 4500MHD, BTW, with Intel's drivers.