Thunderbolt display "burn-in" (vertical stripe)

I got a 27 inch Thunderbolt display about 2 months ago. Last week, I started to see a display problem.

I have a vertical grey stripe (about 3 inches wide) down the middle of the screen. If I look closely, I can see a shadow from the image (web page or application) that was previously under the stripe.

I took a picture with my phone. The dynamics of taking a digital picture of your monitor prevent it from coming our right, but you can definitely see the vertical line.

https://www.flickr.com/photos/122443354@N07/13659301233/

I have a 13" MBP hooked up to the display. I don't think it's the graphics card because I hooked the MPB up to another display and that works just fine.

When I take a screenshot, the distortion isn't shown.

Have any of you seen this before? Do you know what might be causing it?