Thanks for your reply.
I am not sure if I understand you correctly.
With sidebar, do you mean my menu?
I am certain that you are right, I am trying to find the error, and fix it. But I am unsure about how that’s done.
Basically I want a responsive layout where:
header is 100% width.
menu 25% width.
I based my theme on a combined starkers + 1140px grid, and I tried putting my content into the predefined column divs.