Ahh.. glad to hear you found the problem. The localhost thing is new from Facebook, as of about a month ago. Before then, the Like button would show on localhost.
We'll keep it in mind more when responding to questions about it's disappearance and see if there's something we can do in-code to warn users as to why it may not show.
As for Pinterest, there was no attachment in the post. Please make sure you click the green arrow next to an image you upload to actually display it. We'll gladly help look into it however we can. An image may not be enough to find a conflict though, without being able to see it 'live' and understand how all the CSS and other HTML on your site could be conflicting.. just so you know.
Thanks,
Alex