Why is Updating Projects in iMovie 10.0.7 from 8.0.6 not working properly?

I have made a project in iMovie 8.0.6 which i would like to import into version 10.0.7 so that I can edit it the way any normal project would be edited; however, the function "Update Projects and Events" is behaving curiously. When I click on it, i get a window that says "Movie could not find any projects or events to update." which I assume means that all the projects in it's library are updated. I have both versions of iMovie currently installed on my Macbook Pro, and in the older version the projects appears in the library and is editable, but in the new version it doesn't appear. There are other projects in the library that have been distorted, namely one video in particular has the audio that I used, but the video is from something completely unrelated. Some projects are just blank screens, with no content, but have the titles appended. In the library, under Updated Projects, I have the various projects with the thumbnails next to them listed in the upper left quadrant of the application window, and then a line break appears with some clips of other projects, one of which is the one I would like to work on. The problem is that this project is saved in this library as a finished movie, with all the transitions and audio and all the clips saved as one continuous film, so I can't select individual clips, change the audio, or change the transitions. My reason for wanting to use the newer version is so that I can make use of the picture in picture function so as to consolidate the film, and make it more concise. This requires me to select clips and to layer them into one screen, but I can't do that if I can't isolate the clips. The alternative is to start all over again, which I may have to do, but would like to know if this is possible at least for the future.