CFT upgrade disables post thumbnails

CFT has been working great up to 2.1.1. After upgrading to 2.1.2 and then 2.1.5, featured images don’t show up as thumbnails (such as in related post) anymore.

I rolled back to 2.1.1 and they are working once again! The site is at http://carboncostume.com.

http://wordpress.org/extend/plugins/custom-field-template/