Hi, having spent 30 minutes wondering why my galleries were now appearing as thumbnail galleries rather than slideshow galleries, eventually figured out it is probably to do with a flash update, and if you are using Chrome, you need to enable/re-enable Flash. See:
http://helpx.adobe.com/flash-player/kb/flash-player-google-chrome.html
I worked this out by trying to preview the Optima skin on the Skins admin page, and was informed that I need to update Flash. Once I had enabled Flash, my galleries were back to full screen.
