Disappearing pictures in post through links

I'm new to WordPress and hoping somebody can help me with a disappearing picture problem. On my site (http://kitchenjourneys.com/) all of the pictures are appearing on the home page, but many (not all) of them disappear when you go to a post through the links on the right sidebar or the category links on the left. For example, click on 'steel-cut oatmeal' in the links menu and you will see small rectangles where pictures are missing that appear on the homepage. This problem just started today, and I'm so frustrated. Any ideas how I can fix this? Thanks!