There's an unofficial
Some of the MD5s are different; I haven't investigated why yet.
Today Apple released a new security update for Mac OS X. This is an update to the last security update previously discussed on Slashdot. Many users of older Macs with the original AirPort card discovered that the previous version of this update caused wireless networking to fail when waking from sleep, an issue specifically addressed in the new version of this update.
When all else fails, read the instructions.