Hi,
As far as i know there is no command enable-external-services, what you could try is, running the commands;
/sbin/e-smith/signal-event post-upgrade
/sbin/e-smith/signal-event reboot
Then in the e-smith-manager re-setup PPTP connections, in the "Remote Access" section.
Don;t know if this will work, but it's worth a try,
Let me know how it goes,
Rob.