Comment 6 for bug 570828

Well, if NetworkManager can't be used by default (I agree that's a bit late :-), I think we need to revert the patch. See:
http://bazaar.launchpad.net/%7Eubuntu-branches/ubuntu/lucid/gnome-system-tools/lucid/annotate/head%3A/debian/patches/10_disable_interfaces.patch

But you'd need to discuss this with one of the core devs responsible for that, since they introduced this patch intentionnally, and reverting it will be a kind of regression for all other Ubuntu flavours.