FCPRescue

FCPRescue is a must-have app for FCP users. If you don't already know, FCP's preferences aren't the most reliable files on the planet so one of the first troubleshooting steps to take when FCP gets weird is to trash it's preferences.

FCPRescue makes this simple and it backs them up for you when you have a working set (which you can restore later).

Download it now and keep it nearby.