Apple released Mac OS X 10.5.1 Thursday afternoon, nearly three weeks after the Leopard launch. Apple states the update includes "general operating system fixes that enhance the stability, compatibility and security of your Mac," which also includes a fix for a major problem that could result in lost data when moving a document from one hard drive to another.

The update corrects an issue with saved passwords for wireless networks, lets password-protected AirPort Disk accounts display in the Finderis Shared sidebar, improves the reliability of Back to My Mac-enabled computers appearing in the Finderis sidebar, and improves support for D-Link NAT gateways. It also restored the progress bar in Disk Utility, corrected a reliability problem with email alerts in iCal being delivered, and fixed several bugs in Mail.

The Firewall Block All option was renamed Allow Only essential services, and the update also fixed a code signing issue with third-party applications.

The update also corrects drive formatting issue some Time Machine users have been experiencing, and fixes a problem where restored files were appearing in the backup hierarchy instead of the folders where they belong.

Additional information about the updater along with a complete list of updated features and fixed issues is available Appleis Web site.

Mac OS X 10.5.1 is available through Appleis Software Update application, or as a downloadable installer from the Apple Support Web site.