That's because you are using
SITE PRELOAD option, and after editing pages, you forgot to
RECREATE site object. Thus, some pages in your site object are stale (not updated), and will be serving images that don't exist any more. Go to Panel > Tools > Preload > Click
Create Site Object, and everything will be ok.
This is why the errors appear when navigating to the page from the menu (using the site object), yet works entirely fine when accessing the page directly:
http://www.belovephotos.com/galleries/
The
site preload option is an incredibly powerful feature. BUT, if you are going to use it, you will need to refresh (recreate it) it after making changes to your pages. If you don't want to keep it updated, disable it from Settings > Advanced.