Sidebar and CSS mess

I felt that I needed a sidebar again. It is broken at some pages though because I can’t figure out where the problem lies. I expect it to look like it does on blog’s main page exept for that input. That is with Firefox I also plan to add a blogroll. All opinions welcome.

Edit: Defining a width for an element can make things better. Since I had just content div without any div beside it worked, but after adding sidebar with negative margin, it just didn’t cut it anymore. Now I need to figure out input and test IE and Opera as well.