Image permalink 404

I changed my permalink structure today from /%category%/%postname%/ to /%postname%/.

Since the change, the permalinks for my uploaded images have stopped working. The permalinks go to a 404 page now. The image permalink URL’s look like this…

site.com/post-name/image-name/

I have other sites where my original permalink structure was /%postname%/ and the permalinks for images work, so there must be something I need to change to get the permalinks working on this site.

Any help is appreciated.

– Thanks