AirPort Client Update 2009-002
This update is recommended for all Macintosh computers running Mac OS X Snow Leopard 10.6.2 and includes fixes for the following:
Inability to turn AirPort on or off in some cases after upgrading from Mac OS X Leopard
Inability to create a computer-to-computer network, or share the Web connection on some MacBook, MacBook Pro, and Mac mini computers
Orginal post by Mike