Since Fedora 13, I have been unable to use the nm-applet on KDE. It seems like KNetworkManager is the default in KDE on Fedora 13.
Try to get the knetworkmanager-openvpn and knetworkmanager-vpnc packages installed on your fedora instance.
$> sudo yum install knetworkmanager-openvpn
$> sudo yum install knetworkmanager-vpnc
The nm-applet settings for vpn are all lost. So you will need to login to gnome to get those settings and input them into knetworkmanager.
But there are some pending bugs because the knetworkmanager vpn is not really working for me (and also a co-worker). Keeping fingers crossed to see if a future update will fix it.