Apple has released an update to Final Cut Pro, bringing it to version 3.0.1. This version seems specifically aimed at fixing a problem that caused the application to quit suddenly. From Appleis Knowledge Base:
Use this Updater to prevent the following:
Some dual processor computers may unexpectedly quit when Final Cut Pro 3.0 is installed on Mac OS X.
Final Cut Pro 3.0 will unexpectedly quit when you open it if the Internet System Preference pane only contains partial information. This problem can occur on both single and dual processor computers. This Updater will prevent this problem from occurring, but it will not add information to the Internet System Preference pane.
For more information and to download the Final Cut Pro version 3.0.1 Updater, stop Appleis Knowledge Base web site.
Pay special notice to the note at the end of the installation instructions. The information may help with problem updates.