I am having the exact same problem with the same model of macbook pro (13'' 2011 core i5 4gb ram).
I tried your trick but it didn't work.
Only the background (sky) and some objects (like some windows, signs and the dog's shed) are displayed. But when I change some settings in the menus, like for example, change to window instead of fullscreen, then the entire world displays properly for only one frame.
Hope this helps you solve the problem.