I am having this very same issue as well. Never had any problems at all with KSP, either modded or un-modded, until the BETA update. I cannot exit buildings once entered - except VAB - and the 'Quit Current Game' button in the pause/game menu doesn't work either, although all the others do (which means a forced exit and reload of the game). I've tried three new career games, and a fresh install, all to no avail. This is making it very frustrating and starting to ruin what is otherwise a very enjoyable game. Any help to solve this would be greatly appreciated. BTW, I'm running on a HP Pavilion G6 with Win7, 4GB memory, and dual graphics, and never had ANY problems previously (if that helps). EDIT: In addition to this, I cannot recover vessels once they have returned to Kerbin either.