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 detailed information on this update, please visit this website: http://support.apple.com/kb/HT5167.
For information on the security content of this update, please visit: http://support.apple.com/kb/HT1222.