The Delaware Trip post has an over-sized image in it that is driving your sidebar to the bottom. Here are the mamximum sizes of images that you can use without breaking your blog's lay out http://faq.wordpress.com/2006/09/25/how-big-can-my-images-be/
Here is some unsolicited advice that will help you avoid these problems and decrease loading time for your readers. Your front page has huge images and lots of embeds on it and too many posts.
Reduce the number of posts shown on the front page. -> Options -> Reading
Blog Pages
Show at most: ___posts
Click "Update Options"
Optimize your images before uploading them.
Use smaller images and link them to the full sized images.
This gives your readers an option of clicking on them or not.
Shut off Snap Preview
-> Presentation -> Extras
Uncheck the checkbox and click "Update Extras"
HTH
http://faq.wordpress.com/2006/05/08/optimise-your-images/