Unable to change kde email client

Hi Fedora 16: kde 4.7.3 In system-settings / Default applications I'm setting "Email client" to /usr/bin/thunderbird after checking the "Use a different email client" button. Opening a mailto: link in dolphin or firefox or xdg-open or kde-open starts kmail2 and gives the following message on the terminal: QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave. Can anyone else confirm the inability to change the default email client this way please. Any ideas how to work around this? Thanks Roderick