My 2012 27-inch iMac has image retention

I finally got my 27-inch iMac today and the first two things I decided to do were install Guild Wars 2 and copy data from my external drive. I minimized the GW2 installer and noticed that I could still see it on the desktop. I moved the copy status out of the way and could still see it as well.

Is anyone else having this problem? I don't want to go through what others have with the Retina MBP. I believe all of the iMacs are using LG panels, so I'm not sure if it is worth exchanging over.

http://img547.imageshack.us/img547/4158/photocn.jpg

http://img248.imageshack.us/img248/8066/photo1adq.jpg

IR TEST: http://www.marco.org/rmbp-irtest.html

THE SAME HAPPENED MACBOOK RETINA https://discussions.apple.com/thread/4034848?start=0&tstart=0

the new IMAC SCREEN ONLY LG :'(