QuickTime 7.1 delivers numerous important bug fixes and addresses critical security issues. This update is highly recommended for all QuickTime 7 users. 

Important Notice to QuickTime Pro Users

Installation of QuickTime 7 will disable the QuickTime Pro functionality in prior versions of QuickTime, such as QuickTime 5 or QuickTime 6. If you proceed with this installation, you must purchase a new QuickTime 7 Pro key to regain QuickTime Pro functionality. After installation, visit www.apple.com/quicktime to purchase a QuickTime 7 Pro key.