I'm having the same problem with NM in Kubuntu Karmic since an update.
My solution was to restart the Knetworkmanager service it then segfault
crashed, after that it just worked right again and connected to my wpa2-psk
network without a problem. I have to do this everytime I reboot now.
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Fixed ? I set the N.M nm-system-settings.conf
managed=true
it was unmanaged before.
now this time I didn't have to restart the service at
boot. strange!?
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knetworkmnager doesn't connect to wpa2-psk secured wlan while nm-applet
connects without problems