The IE7 problem is because you have inner elements bigger than the outer elements and it pushes things wide.
For example the container is 1023xpx but you have given some elements a 1023px and padding as well.
Here's one yof them:
You can check this is what's happening by hiding the overflow on one of the containers.
Everything click back into place with the above code. Of course that's just a band aid and not a cure to the problem so you need to go back and make sure everything fits inside the containers that they are supposed to including margins, dimensions padding and borders etc.