This happens most likely because the driver could not properly unloaded before starting to scan. Possible reasons can be: • You have another user logged in with Fast-User-Switching • You are running the Classic environment • You are running an application which locks your AirPort connection, such as Internet Connect.app or sometimes Konfabulator. • You are using a 3rd party driver that is incompatible with KisMAC. Currently supported: AppleAirPort.kext, IOXperts, MacSense, WirelessDriver.kext (with a patch), CiscoPCCardRadio.kext If you cannot work something out, post to the forums. Make sure to includes the following: everything listed on this forum post, a copy of your system.log, and the output of a ps ax. This helps to ensure that we can find your problem.