Have you guy tried splitting the debugger menu from the actual game window. I've notice that If i am debugging with both the game and the menu on one window It tend to fuck up but if i manage to split it up it runs like a charm. such as debugger in one stand alone window and the game in the other window.
The problem may just be the debugger itself that is taking a toll on the engine. and is not calculating properly and perhaps that there is a frame-rate math that is causing itself to loop infinity times over. but that just a guess on my part.