Pinterest Thumbnails using short code

The thumbnails will not display properly. Is there an issue with compatibility between the plugin and the most recent upgrade to WP? I am using the short code on a page, and no matter what size I put the thumbnails in the parameters…or leave it at the default, the thumbnails come in stretched and unrecognizable. This pretty much makes the plugin unusable.

Any ideas?

http://ww.wp.xz.cn/extend/plugins/pinterest-rss-widget/