Problem: Images resized automatically with strange behavior.
 

When I add an image to a post, the image and text included are resized to a set width (not filling the post area).

Note: Image is much larger than the post area and has been automatically reduced in both examples.

example:
http://www.themodelhangar.com/images.../postimg-1.jpg

If I go back and edit the post and save, it returns to fill the post width completely.

example:
http://www.themodelhangar.com/images.../postimg-2.jpg

However, this is temporary. If I refresh the browser it returns to the first example.

Anyone know whats causing this and how to fix it so that the images and text always fill the post area?