I'm using FCP 3 and it keeps quitting just as all the windows are starting to open after double clicking the project. Do I need to defragment my g4 or is it another problem? This has never happened before.
First thing I'd try is dumping my preferences. Sounds like perhaps something in there has gone corrupt on you. FCP Rescue is a great program for that, you might want to get it after you get things working again (won't do you any good in the immediate future though).