Less than three weeks after its launch, the first update to Mac OS X Leopard, version 10.5.1, has arrived, bringing with it a number of bug fixes and security updates.

While Leopard's arrival was greeted with overwhelmingly positive reviews, a number of problems did hit early adopters. Most notably, some users found that when they were moving files across a network and the destination drive disappeared, Finder still deleted them from the source. Apple says it has fixed the problem, although it may be a little late for an unlucky few.

Other fixes in Mac OS X 10.5.1 include an issue with saved passwords for wireless networks; an issue that could produce an alert when creating disk images using Disk Utility or Terminal; an issue in which Microsoft Windows shared folders may be read-only when connected via SMB; and a code signing issue that prevented some third-party applications from running.

A handful of changes have been made to Apple Mail to resolve a number of minor problems, and Apple has fixed two issues related to Adobe Flash, one involving a text-drawing bug and another related to file uploads.

Time Machine, a new feature in Leopard, is now fully compatible with drives larger than 512GB, and Apple has resolved an issue in which files restored in Time Machine may be restored to the backup hierarchy rather than the folders to which they belong.

Also included in the 10.5.1 update for Leopard are a number of security fixes released for Tiger earlier this week. 39 separate security vulnerabilities were patched in that update, although its not clear how many affected Leopard; most of the issues involved Safari and the Mac OS X kernel.

Mac OS X 10.5.1 can be downloaded via Software Update, and more information is available from Apple's support site.