I just upgraded the Linux kernel on my laptop to 18.104.22.168, and in the process had to upgrade the ipw2200 (Intel Wireless Drivers) to version 1.0.8. After the upgrade, no matter what I did, I couldn’t get wpa_supplicant to work – it kept returning an error saying:
ioctl[IPW_IOCTL_WPA_SUPPLICANT]: Operation not supported
I finally figured it out – the new kernel supports Wireless Extensions version 18, which support WPA natively, and the ipw2200 drivers have been updated to use these WPA calls instead of it’s own. So, you need to change the ‘-Dipw’ on your wpa_supplicant startup line to ‘-Dwext’. Once I made that change, it fired right back up – wasted a *lot* of time trying to figure it out, too!