Is your drive a clone with the same disk name or just a copy of the folders and files? When you first opened the project did you have to reconnect files?
It was foolish of the producer to change to FCP7 mid project. Although she can read your projects, she can’t easily make any adjustments and send you a project to open without using XML. Nothing wrong with the project files being renamed as a ‘save as’ function. Is that what you are doing?
Of course render files at your end won’t be on the producers drive so they will alwyas have to be redone. Are the files that want to be reconnected clips that you have applied a render to? In other words can you see a pattern in the files that need reconnecting?