Strange Repeating Background-image behavior

I am having some strange behavior from the repeating background-image. It doesn’t extend the length of my posts. I admit, the posts are REALLY long at the moment, because I haven’t formatted them at all, and they are image heavy, but either way it illustrates the issue well. What’s odd, is depending on the system, it behaves differently. In IE, it works fine. In FF on my laptop, it starts at the top, and ends somewhere in the middle. On FF on my desktop, it starts mid way down, and ends before the bottom.

Here is the site as it sits right now: http://mattandjentry.com/otgb/. I have set the background color to green to make the backgroun-image more visible (It’s really light).

Another strange note… the background-image moves when you hover over the images in the post. I’m confused.

Edit~ I figured out why it was showing up in the center on one browser. The CSS positioned the background to center. Fixed that, but it’s still not repeating to the bottom, and it still moves when you hover over images o_0