The images are inside of a <div> tag which has the following CSS defined:
div.inlinepostimage {width:350px;overflow:hidden;}
Basically limits the width to 350px and anything over that is hidden.
There's a javascript function on the image which is supposed to
execute when the image loads and another when the page loads (as a
backup). Basically for inline images, the dimensions should
resize dynamically to be no more than 350px in height or width.
I honestly wouldn't change how you're doing your images. They're
fine. It's an issue with individual browsers and how it's being
displayed. It's affecting some browsers, but not all. It
might be a minor modification to the javascript I need to make.