QuickTime 7.5 improves application compatibility and addresses security issues.
This release is recommended for all QuickTime 7 users.
For detailed information on the security content of this update, visit this website: http://www.info.apple.com/kbnum/n61798.
The update is available now via Apple Software Update or you can download it from the Apple site here for the UK. It was expected with the release of the iPhone 2.0 software. It has new playback controls, offers up t 24 channels of surround sound and uses the new H.264 video codec for much improved quality.