So, I've been working on a project on IMovie 11' since November w/ music & clips I downloaded from YouTube. I was more than half way finished with it, it was perfect & all of the sudden, it went nuts on me. The first thing that happened is an entire event folder of video footage greyed out - I assumed it was because I had over 10 hrs worth of clips & it was too full, so I moved some to another folder & it worked - all the clips came back & I could see them in the project. The next time I opened the program, it was saying "Optimizing Video" & loading something. Then, it wouldn't even let me playback the project, edit or add anything to it. The thumbnails were still in the project & all the clips played within the event folders, showing the orange line indicating what was in the project ... but when I try to playback the project, it's just a grey screen & plays random audio from another one of my video projects. I even tried exporting the movie & saving it to my computer - when I played it, it was a totally different video project! None of my other video projects will play either, it only plays the audio & shows the grey screen. ALL the clips play in the event folders, so I don't understand why my projects won't playback. Anybody have any idea what's going on here? It's really not letting me do anything & I'm really upset because I've worked so hard on this If anybody knows the problem or how I can fix it, I really appreciate the help! If I have to, I might have to redownload IMovie & start over. I know there is a new version of IMovie, but if I update will I be able to get all my old projects & do you think they will work? Thanks!