I fought with this in my last class and now ran into a support case with the same issue. What's the problem? 2013 seems to lock up anytime the Project Wide or Surfer dialogs open. The Ribbon grays out and nothing seems to work... until you press Esc. Then everything seems fine again.
The problem is the Project Wide "Select Drawings" and Surfer dialog were at some point moved to a second screen.
I called Autodesk Support and was told this is an issue they are aware of. The problem has been fixed and they are expecting it to release with SP1 later this month. Until then, use keyboard shortcuts to move the dialog back on your primary screen and it will stay there. Place it back on your secondary screen and the next time the dialog is called for it will open off screen again.
Press and release Alt then the down arrow followed by M and then the down arrow again. This will stick the dialog to your mouse. Move the dialog back onto the primary screen. It will stay there.