Apple just released an update to their Pro Application support for Mac OS X. According to Apple, this update "improves reliability for Apple's professional applications." This update is recommended to all users of Final Cut Studio, Final Cut Server and Logic Studio. Final Cut Pro 6.0.4 and Compressor 3.0.3 are applications included in the update.
You can download this update by opening Software Update (choosing Software Update from the Apple menu) or by downloading the installer package from the Apple Support Downloads site. You can visit the Pro Applications support note for more information about this update.