I installed this plugin today, and now when you try to pin from my blog via the "Pin it" bookmarklet, all my images show the "sorry, can't pin this image" error. Yikes! Unfortunately, this problem continued after I deactivated the plugin so it left some sort of lasting impression.
The images to which I've added the "pinthis" class can still be pinned, it's just pinning from the bookmarklet that doesn't work.
Any help is so appreciated! I've reactivated the plugin for troubleshooting purposes.