Apple today released Mac OS X v10.6.3 Update which is recommended for all users running Mac OS X Snow Leopard and includes general operating system fixes that enhance the stability, compatibility, and security of your Mac, including fixes that:
• improve the reliability and compatibility of QuickTime X
• address compatibility issues with OpenGL-based applications
• address an issue that causes background message colors to display incorrectly in Mail
• resolve an issue that prevented files with the # or & characters in their names from opening in Rosetta applications
• resolve an issue that prevented files from copying to Windows file servers
• improve performance of Logic Pro 9 and Main Stage 2 when running in 64-bit mode
• improve sleep and wake reliability when using Bonjour wake on demand
• address a color issue in iMovie with HD content
• improve printing reliability
• resolve issues with recurring events in iCal when connected to an Exchange server
• improve the reliability of 3rd party USB input devices
• fix glowing, stuck, or dark pixels when viewing video from the iMac (Late 2009) built-in iSight camera
Mac OS X 10.6.3 is available via Software Update and also via standalone installers.
More info and download links here.