Hi I was wondering if there is any way to open a 5.1 project in 5.0, when I try and open the project I get a "File's format is too new for this version of the application."
Go back to FCP 5.1 and export out an XML 2.0. Then import the XML file into FCP 5.0. Look in the File menu for the commands, and in the manual for more info on XML.
I just did this last week on a small project, and it worked great!