Images not being promoted to front page

I'm currently testing out my site to make sure everything works ok and have found a problem.
Images when uploading are not being promoted to the front page when I have set them to do so, also they seem to 'disappear' once uploaded, meaning they do not appear in the category list to which they were uploaded to or anywhere on the site. The only way to access them is to point to the URL of the image once uploaded.

Does anyone know how to fix this so images do appear on the front page?

Thanks in advance.