Apple has updated Snow Leopard to version 10.6.3. You can obtain it via the Software Updates component of the Mac OS X Systems Preferences app. According to Apple, general operating system fixes and improvements provided for:

° Performance of Logic Pro 9 and Main Stage 2 when running in 64-bit mode;

° Printing reliability;

° Sleep and wake reliability when using Bonjour wake on demand;

° A color issue in iMovie with HD content;

° Glowing, stuck, or dark pixels when viewing video from the iMac (Late 2009) built-in iSight camera;

° An issue in which the Finder reports a -36 error when copying directories to a drive formatted as FAT32;

° Reliability of photo screen savers;

° Compatibility issues with OpenGL-based applications;

° An issue in which shadows in PDF of Aperture book are black instead of gray;

° An issue in which the microphone level in iChat may not increase the volume after reducing it to prevent a feedback event;

° The reliability of certain third-party USB devices;

° The Accounts preference pane can now limit log-in to members of groups hosted by a non-Apple directory service, such as Active Directory;

° DNS server ordering as specified in Network Preferences and DNS reliability;

° The reliability and compatibility of QuickTime ;

° Data collection: Mac OS X 10.6.3 can collect diagnostic and usage information from your Mac and send it to Apple for analysis automatically. The information is only collected with your explicit consent, and is submitted anonymously to Apple. For more details, see this article.
 

Mac OS X 10.6.3 also sports AirPort and wireless networking fixes for: general reliability for wireless connections; improvements to 802.1X reliability, including closed network connections , and WPA2; and sleep/wake reliability for current iMac models when connected to 2.4GHz wireless networks.
 

Date and Time fixes are provided for Daylight Saving Time rules to reflect recent changes in areas including Argentina, Fiji, Pakistan, and Antarctica.
 

Directory Services fixes are provided for: an issue that could cause the system to become unstable or unresponsive when bound to an LDAP server using SSL; and an issue in which the 802.1X Loginwindow Profile is in place, but the wireless network is not available, directory authentication over Ethernet will now succeed.
 

File Services fixes are provided for: an issue that could prevent saving files from Microsoft Office 2008 to an SMB server volume; issues copying, renaming or deleting files on an SMB server volume; and clear-text authentication enabling to an SMB file server.
 

iCal fixes are provided for: changing the invitation list for a single instance of a recurring event will no longer "un-book" the location of the meeting; an issue in which new invitations on a Microsoft Exchange server might not appear in the Notification pane; and properly showing recurring Microsoft Exchange events which have a set end date. For details, see this article. 


Mail fixes and improvements are provided for: an issue that causes background message colors to display incorrectly in Mail; signing and encrypting messages, such as when using an Entrust PKI (Public Key Infrastructure); synchronization of the "Sent" mailbox on a Microsoft Exchange server; and an issue that could cause Mail to delete mailboxes on a Microsoft Exchange server that is hosted behind an Internet load balancer.
 

Mobile Accounts fixes and improvements are provided for: home directory synchronization when the home directory is stored on an SMB file server; properly warning mobile users in an Active Directory domain about upcoming password expiration; creating a Mobile Account that uses smart card authentication, without using a command-line tool; and reliability in background synchronization.
 

MobileMe fixes and improvements are provided for: an issue in which movies could not be viewed in Safari when visiting www.me.com/gallery; reliability of iDisk Sync; and reliability of syncing calendars.

Parental Control fixes and improvements provided include: restoring Safari bookmarks functionality to parental controls users; better handling of Safari bookmark management when using Parental Controls; more reliable application launch restrictions when using Parental Control.
 

Rosetta fixes provided include an issue that prevented files with the # or & characters in their names from opening in Rosetta applications.
 

System Imaging fixes and improvements provided for are: the asr command, which now accepts the "--allow fragmented catalog" option, for restoring images that have a fragmented catalog file; and the installer command, which can now be used to upgrade a Mac OS X 10.5 system with a QuickTime 7 Pro key installed to Mac OS X 10.6.
 

Time Machine fixes and improvements provided are: reliability from Time Machine-to-Time Capsule backups, including multiple computers; an issue with Time Machine in which system backups could be restored onto unsupported Mac configurations; and an issue in which a Time Machine backup might not work using an AirPort connection.
 

Xsan fixes and improvements provided include the reliability of Fibre channel connections to an Xserve RAID and an issue that could cause the size of certain Fibre channel LUNs to be mis-reported.
 
The Mac OS X v10.6.3 combo update also includes improvements provided in the Mc OS X 10.6.1 Update and the Mac OS X 10.6.2 Update.