The problem with the snapshot is that you a) haven't cleared the floats above and b) haven't contained the floats within and c) used height:100% which can't really be used at all and d) you have added borders to 100% wide element making it too big.
(See the faq on 100% height and as to why it's of no use to you other than when hacking ie6)
/* border:1px solid red;*/
clear:both;/* clear floats above*/
overflow:hidden;/* contain floated children*/
What was the issue with the footer again? It looks at 100% to me. I set the background to red and it stretches all the way across. Or did I miss something.
You do have a typo here:
<span class="TwitterTime"></span> </div>
That closing p tag cannot be there and cannot contain block elements.