Why hasn't this Facebook sharing bug been fixed?

Anyone that manages a Facebook brand page will know what I'm talking about here. On far too many occasions to ignore, sites with Facebook sharing or like buttons are completely broken when a user visits the site using Facebook as a page.

At first I thought it was just a small bug but after noticing more and more sites that suffer from this I can't understand why it hasn't been flagged up and fixed yet.

Here are some examples of sites.

http://mike-hostetler.com/blog/2013/02/06/5-reasons-a-ceo-should-champion-responsive-web-design/ http://politix.topix.com/homepage/4480-obama-to-name-ceo-of-outdoor-equipment-co-rei-as-interior-secretary http://www.suntimes.com/18045729-761/postal-service-to-cut-saturday-mail-to-trim-costs.html

These are just a couple that I've noticed in the past few hours...

Any ideas on why this glaringly obvious error has not been rectified?