There is a Gotcha in the NG pre r1408 code:
The new NG drivers are confused for an earlier ("old madwifi") driver and are perniciously managed by the Draknet|drakconf|MCC. You will need to both hand manage scripting the proper operation of the atheros card, and do damage control on the drakconf and Mandrake Control Center (MCC)/network configuration scripts effort to maintain your system and wireless network.
The new madwifi-ng code has a new first step, where wlanconfig creates ath0 (The Old Code Used modprobe ath_pci for this). NB: It is demonstrably easier to install the NG code fresh, especially on the 2006 releases. If you have a prior install of the Madwifi drivers, see the notes at the bottom of UserDocs/Distro/Mandrake.