I am using Windows Live Movie maker on Windows Vista. I am also creating the project on my school desktop computers' Live Movie Maker. 

After I created and saved my work at school, and then tried to open the project on vista, the file is not compatible with it or it may be corrupted. Yet when I go back to school, it works. So what is the problem!??

 How do I fix it so that I can work on it at home and and at school?

Please help. This is extremely important and I cannot seem to find the satisfactory answer!