Right, one problem might be that your CPU cooler has not got anything directly in line with it to disperse the heat. Your cooler is great for cases with side-panel exhaust fans, but i can see it pumping alot of hot air around the case instead of outside the back exhaust. Might be worth getting a different cooler that blasts air out the back as opposed to straight up.

Try tidy those cables up too, Instead of having the unused PSU cables hanging in front of the mobo, keep them right up top next to your PSU.