While looking at Google Webmaster Tools' Crawl Errors, I get a lot of 404 errors related to image files with /feed URLS. I'm guessing that an automatic feed occurs on the image attachment page.
The URL error is: www.mysite.com/uploads/image.jpg/feed
Linked from is: www.mysite.com/imageattachmentpage
Not sure that this is a theme issue, but I'm not sure how to correct it either. It's probably more of an annoyance than a real problem but it's messy to sort through.
Also, it's weird that when the post is changed to another author that the image attachment page doesn't change with it. Not sure if that is a WP or a theme setting.