Button doesn't show on aligned images

First – thank you for this plugin! Makes it so easy for people to pin our content, which images are a big part of.

I am having an issue getting the pin it button to show on the images that I place at the beginning of the post.

See http://paleodulce.com/peppermint-mocha-nut-creamer/ for an example. All of the full sized images in the post that are not aligned are showing the button fine, but the image at the beginning is not. Could it be due to the fact that it is aligned right or re-sized? And to your knowledge, is there any solution to this?

Thanks so much for any help (and for the awesome plugin)!!

http://wordpress.org/plugins/pinterest-pin-it-button-for-images/