Apple on Monday released Mac OS X 10.5.5, a recommended update for all users of Mac OS X 10.5.x Leopard that includes over a hundred bug fixes and enhancements. As of press time, the 321MB update was only available via the Software Update mechanism located under the Apple menu of your Mac.

In addition to general stability improvements and over two dozen security enhancements, the update addresses issues with Address Book, Disk Utility, iCal, Mail, MobileMe, and Time Machine. Here’s a detailed list of those fixes.