WordPress loop tag breaking layout when added somehow…

I recently overhauleed my website which incorporates wordpress into it. I set up my layout so that there is a top area, a middle area and footer area.

In my middle container div, I have the content div to hold all posts(and the wp loop) and floating beside it is a div acting as the sidebar to hold my twitter widget.

Everything is happy and sunny with my layout until I add in the wordpress loop tag. Once the wp loop tag is added, the layout suddenly breaks and the sidebar jumps to the next line under the content div.(when I take the loop tag out, everything is fine again)

I can’t figure out what the F is going on. I started over completely thinking I had flubbed something along the way but am getting the same frustrating result.

Here is the php code….

[huge chunk of code moderated - please use pastebin.com for this]