It's a bit of an unforynate thing that I am only able to edit CSS properly when it is directly edited and is also completely mine? I don't really have the heads or tails of Forumotion styling at this point, it being so long.
I do have a feeling that it's something in the CSS float rules, or lack therof. Do you know how to use the developer tools for your browser? If so, attempt to inspect the elements affected, take note of their IDs and classes, and hunt for them in the style rules themselves, if you have direct access to the CSS.