I have an issue on Mac OSX 10.9.5 where, on game boot, the steam overlay will show "click shift+tab to pull up the steam overlay" in the bottom-right corner of the screen. as soon as this overlay appears, the whole background changes to be yellow and black. no text appears, the background image goes away. it's unplayable. I LOVE this game, and I know it has worked in the past. please fix. thanks!