Comment 3 for bug 358061

I've used the kubuntu-experimental overlay before I upgraded to jaunty one month ago. And it seems there was still a stale package 'network-manager-kde' installed that caused the crash. I uninstalled this package and installed 'plasma-widget-network-manager'. The applet starts now without crashing plasma.

Thanks for pointing in the right direction - I hope this helps other people who run into the same problem.