OG tags present, but Facebook posts still broken

So, the proper og tags are automatically pulled into the header of each article page. However, when we try to post a link from www.dailypost.vu it only shows a small box with the site's domain in it. No headline, photo or description.

One major stumbling block to this was almost certainly the robots.txt file, which in its default state prohibits all but a small number of whitelisted bots from crawling the site. We have now fixed that, but the Open Graph Debugger still comes back with "Document returned no data " when testing our pages.

Everything appears fine with the CNAME. There is a theory in the office that our abysmal time-to-first-byte is the culprit. Any further thoughts on how we can make our posts to Facebook work properly would be appreciated.

Regards,
Hunter