AirPort Update 2005-001
Now available via Software Update:
This update fixes reliability and resolves AirPort compatibility issues with certain third party 802.11 cards and access points for Mac OS X v10.4.3 and later.
Apple also recently released the Mac OS X 10.4.3 update.
The previous Airport update was in July 14, 2005.
Update: One user reports that Motion 2.0.1 has also recently been updated.