After a recent clean install, unable to open all tracks / instruments in saved GB projects.

Hi

Since a clean install about a month ago, I am unable to open all saved Garageband projects without tracks or instruments missing and GB wanting to search for the files missing.

I am not sure if this is something to do with 10.8.2 or more recently with 10.8.3 or a problem installing from the oringal DVD and chaning the date my mac. I had so many problems previously trying to install iPhoto from the DVD I have now bought the app from the App Store.

Thanks in advance.

Matt