Apple has released Mac OS X 10.5.6 to customers this afternoon.

The 10.5.6 Update is recommended for all users running Mac OS X Leopard and includes general operating system fixes that enhance the stability, compatibility and security of your Mac.

Apple details the changes in this support document. Some highlights include:

- Improves reliability of Address Book syncing with iPhone and other devices and applications.
- Improves the reliability of AirPort connections, including improvements when roaming in large wireless networks with an Intel-based Mac.
- Resolves an issue in which pasting text from a Microsoft Office document could insert an image rather than text.
- Includes general improvements to gaming performance.
- Includes graphics improvements for iChat, Cover Flow, Aperture, and iTunes.
- Includes fixes for possible graphics distortion issues with certain ATI graphics cards.
- Mail: Includes overall performance and reliability fixes.
- MobileMe: Contacts, calendars, and bookmarks on a Mac automatically sync within a minute of the change being made on the computer, another device, or the web at me.com.
- Improves reliability and performance for AT&T 3G cards.
- Fixes issues that could cause Time Machine to state the backup volume could not be found.
- Improves Time Machine reliability with Time Capsule.
- Safari: Improves compatibility with web proxy servers.

The 10.5.6 update is available as a free download through Mac OS X 10.5′s Software Update.

WARNING : A warning for all you iPhone jailbreak enthusiasts: Apple’s newest OS software update contains quite a stink bomb—10.5.6 disables the Pwnage tool, making you unable to jailbreak or unlock your iPhone or iPod Touch, the simplest way to work around the update for now is to copy some of the 10.5.5 framework files over the newer ones… or not update.