The 10.7.4 update is recommended for all OS X Lion users and includes general operating system fixes that improve the stability, compatibility, and security of your Mac including fixes that:

Resolve an issue where the “Reopen windows when logging back in” setting is always enabled

Improve compatibility with certain British third-party USB keyboards

Address an issue that may prevent files from being saved to a server

Improve the reliability of copying files to an SMB server

For information on the security content of this update, please visit: http://support.apple.com/kb/HT1222.

See this article on how to verify the authenticity of this update.