Unity 4 Editor(?) main window is white on launch.

Unity 4, Windows 7 64bit, GTX 980.

On fresh install, launch, and creating a new project, the main window is completely white except the File / Edit / etc menus. The welcome window opens and I can see that, but nothing else. Resizing the window makes sections of it black rather than white, but no matter what I can do I don't see anything.

The welcome window and asset browser are visible and work. Seems like just the main window. Editor, if that's what they're calling it.