I noticed today when clicking on post image that instead of showing the larger image it's showing a captcha background image. When I go to edit the page and the image I'm able to reset the path to the image. I noticed that all the image paths are missing "wp-content/uploads" but the folder year and month are there. At the end the ".jpg" is missing and is replaced with a slash.
So an image that is linked to "www.website.com/wp-content/uploads/13/03/picture.jpg" is instead "www.website.com/13/03/picture/" and that captcha image is showing instead.
If you click on the black dog on this page you will see this... http://www.unitedhope4animals.org/2011/01/making-your-own-dog-food/
Permalinks are set to "Month and name" and it's almost as if it's trying to make the image have the same type of path.