According to Apple, Mac OS X 10.5.1 solves problems related to Airport, Back to My Mac, Disk Utility, iCal, Mail, Network, Printing, Security and Firewall, System and Finder, and Time Machine.
The System and Finder has received several updates, including a fix for a potential loss of data when files were moved between partitions from the Finder, a fix for a validation-related issue on the computer after activating the FileVault feature for an account user-specific settings, improved compatibility with the Adobe Flash-based file upload utilities used by the .Mac Web Gallery and other websites and applications, and solved a potential issue related to drawing text in certain Adobe Flash-based websites and applications.
Apple’s Mail app has also been the repository for its fair share of updates in 10.5.1. Mail includes stability improvements when resizing columns in the message viewer or when switching between templates in the message window. Also fixes an issue where attachments contained in an HTML link might not be active in email messages; in addition to solving a problem with email accounts created by using the “Setup Wizard” feature, and where messages were not being sent due to an SMTP connection failure. Smart Mailbox support for the .Mac Sync feature has been improved, and an issue with Tasks disappearing when using Smart Mailboxes is resolved. Additionally, there was also an issue with syncing Mail accounts with .Mac where multiple folders On My Mac appeared in the mailboxes panel.
Time Machine, Apple’s new backup feature introduced in Leopard, has been updated to address an issue related to the formatting of certain drives used with Time Machine (especially MBR drives with a partition greater than 512GB). size, as well as NTFS drives of any size and partition scheme). The update also addresses an issue where files restored with Time Machine could be restored over the backup hierarchy instead of the folders they belonged to.
Updating the Mac OS X Firewall resolves an issue with code signing. Now third-party applications can work correctly when they are included in the Firewall or in the white list of Parental Controls.
Changes made to Airport include the ability to display password-protected AirPort drives under the Shared section of the Finder sidebar; in addition to solving a problem related to saved passwords for wireless networks. The Back to My Mac feature has been updated to allow Macs enabled with that functionality to appear in the Finder sidebar. The update also improves compatibility with D-Lint NAT gateways.
iCal has been updated to address an issue with inviting attendees using a CalDAV account, as well as sending email alarms more reliably. An issue has also been fixed where folders shared by Microsoft Windows might appear as read-only when connecting via SMB.
Disk Utility has also received a number of minor changes, including the restoration of functionality for the progress bar during permission repair. Finally, some issues related to print settings have also been fixed.
Mac OS X 10.5.1 can be downloaded from the Apple website, or through the Mac OS X Software Update mechanism.