I find that when I select from the recent posts list on my left sidebar that only one of the posts will display correctly while the other only shows me the featured image. Not sure what I’ve done wrong.
First try to go to Settings > Permalinks, and click save permalinks again.
If that does not do it, I get the feeling your post pages are being confused by WordPress with image attachment pages.
Make sure that your images do not have the same name as your posts.
WordPress easily gets confused between pages if entity have the same names. If your images have the same name as your posts, you need to change their names. Once your images have a different name than your posts resave the permalinks and check again.
In the same way do not give the same name to category and posts etc…