MacBook Air SMC Update v1.5
About MacBook Air SMC Update v1.5
This update fixes several sleep/wake issues to improve the stability of MacBook Air (Mid 2012) computers and is recommended for all users running OS X v10.7.4.
It also enables Power Nap support for users running OS X v10.8 or later.
For more information, please see http://support.apple.com/kb/HT5394.