I've downgraded my OS from Mavericks to Mountain Lion 10.8.3. It was because of a compatibility issue with an AVID sound interface I'd purchased. I overlooked the fact that my imovie and iphoto versions for Mavericks wouldn't run on Mountain Lion. I'm really stumped now on what to do about that. How to roll back the versions of these applications and restore my photo and movie files. Please, any advice greatly appreciated. Tim.