Apple today posted AirPort 4.0.1 for both Mac and Windows. The update is recommended for all customers with AirPort Express base stations. According to the release notes, the Mac version also includes improvements to Profiles support in the AirPort Admin Utility, and improved handling of WEP keys with third-party access points. The Windows version of the AirPort 4.0.1 update resolves potential issues with certain wireless cards.