I've only put controls inside their own windows (to make dialog type boxes, with text input or sliders). I tried putting a button in the acknex window and it wasn't visible, except when the acknex window wasn't active, (e.g. when i dragged other windows past the acknex window, the button would show up before the acknex window would refresh. I'm not sure why the common controls are being hidden by the acknex window otherwise). I didn't load a level; just had the screencolor set to gray. I've avoided using fullscreen mode because I like using message boxes that popup infront of the window, so I don't know what it does in that mode.