Facebook like button shows wrong pic inside Facebook

I’m using your Really simple Facebook Twitter share buttons for WordPress. I was so happy to find your plugin. It’s so much better than all the others I tried!

However, I’m having one little problem with the Facebook like button. It attaches the wrong article image to the on the Facebook page. In other words, the text that says, “Shawn Nelson liked a link…” and then it shows the link… this shows an image for a different article. You can try liking this page and then viewing your Facebook activity to see for yourself:
http://geekychristian.com/standford-scientists-discover-that-way-ants-search-for-food-mirrors-the-protocols-that-control-traffic-on-the-internet/

Do you know how I can edit the code to fix? Thanks so much!!

http://wordpress.org/extend/plugins/really-simple-facebook-twitter-share-buttons/