The 10.6.7 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:
Improve the reliability of Back to My Mac
Resolve an issue when transferring files to certain SMB servers
Address various minor Mac App Store bugs
For detailed information on this update, please visit this website:
http://support.apple.com/kb/HT4472.
For information on the security content of this update, please visit:
http://support.apple.com/kb/HT1222.