Ever since F10, nm-applet is still used on kde and doesn't work correctly. It always asks for passwords. The issue is with talking to gnome-keyring-daemon IIUC. On my desktop, at least, this is still not fixed. One suggestion is to use knetworkmanager (sp?) instead, but it's not as full- featured (or as nice) as nm-applet, so that's not much of a solution.
