Developer website: Apple
This firmware update addresses an issue where trackpad clicks may not be recognized on MacBook (Late 2008) and MacBook Pro (Late 2008) systems.
The update package will install an updater application into the Applications/Utilities folder and will launch it automatically.
Follow the instructions in the updater application to complete the update process.
For more information about this update, please see http://support.apple.com/kb/HT3288