[SOLVED] Problem positioning divs

[Lautarox]

I'm having some problems locating divs in a web page, I've an upper div, which I want it to be situated in the top, as a login bar, the problem here is that the bar sometimes is not perfectly aligned in the top without setting margin-top to -10px, and is not perfectly aligned also with the entire screen, I've used 100% as width, but some browsers with different resolutions doesn't seem to have problems with it, also the main problem why I'm asking is because I've setted all my divs as relative because the main div's size is continually changing, and I need to put a bar on the right of my main div, but the problem is that I can't get it in the place I want, I've declared it as absolute, and depending on the hight of the main div, it moves..

I'm using Firefox 3.05

Check it if you want..

http://201.231.17.94/apache2-default/carnet/ing/test/

Thanks in advance