The 10.6.8 update 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:
Enhance the Mac App Store to get your Mac ready to upgrade to Mac OS X Lion
Resolve an issue that may cause Preview to unexpectedly quit
Improve support for IPv6
Improve VPN reliability
Identify and remove known variants of Mac Defender
Enhance the Mac App Store to get your Mac ready to upgrade to Mac OS X Lion
Resolve an issue that may cause Preview to unexpectedly quit
Improve support for IPv6
Improve VPN reliability
Identify and remove known variants of Mac Defender