If your FCP 7 is crashing regularly, one simple solution is to trash the preference files.
Quit FCP7.
- Click on the desktop and then Option Click on 'Go' on the top menu.
- You will see a button called 'Library' which disappears when you release the Option button
- Go to this 'Library' folder.
- Find a folder called 'Preferences' in this 'Library' folder.
- Find and delete this file: "com.apple.FinalCutPro.plist"
- Inside the folder 'Preferences' scroll down to find a folder called 'Final Cut Pro User Data'
- Delete the following files : 'Final Cut Pro 7.0 Prefs', 'Final Cut Pro Obj Cache', 'Final Cut Pro Prof Cache'.
Restart FCP 7. Most of your troubles should have gone.