According to Apple, the update includes general operating system improvements that enhance the stability, compatibility and security of its Macintosh computers.
Apple included 10 updates for Mail in the new version, Mac OS X 10.5.3. The fixes include a patch for a stability issue involving the dragging of large attachments to a mail message and reliability problems when users make changes to an offline mailbox.
Apple also included fixes that improve Active Directory binding and login and eliminate a delay when logging in as an Active Directory user in a local domain.
For users of Apple's AirPort wireless networking, the patch improves 802.1x behaviour and reliability. It also enhances reliability when using the Time Capsule, Apple's Wi-Fi basestation and back-up device.
In addition, Wednesday's round of fixes addresses potential privacy issues by allowing users to mark iCal events as private.
Patches for Apple's iChat improve reliability during screen-sharing sessions as well as correcting a problem that left group chats non-indexed in Spotlight.
Apple also enhanced the reliability of Automator, Address Book, Parental Controls and VoiceOver with this update.
Apple recommends users with Mac OS X 10.5, 10.5.1 and 10.5.2 Leopard install this update. Mac users can download the Mac OS X 10.5.3 update via the software Update control panel.
The round of fixes did not address three vulnerabilities in the iCal standalone calendar application, which were reported last week.