edit /etc/xdg/autostart/nm-applet.desktop and add KDE; to the line that has ONLY_SHOW_IN
[Desktop Entry]
Name=Network Manager
Comment=Control your network connections
Icon=nm-device-wireless
Exec=nm-applet –sm-disable
Terminal=false
Type=Application
OnlyShowIn=GNOME;XFCE;
X-GNOME-Bugzilla-Bugzilla=GNOME
X-GNOME-Bugzilla-Product=NetworkManager
X-GNOME-Bugzilla-Component=general
X-GNOME-Autostart-enabled=true
X-Ubuntu-Gettext-Domain=nm-applet