Ok, the header was a problem of my example, I have now a defined size.
The z-index was only to have the content bellow the header (z-index: 2). I want to have #text-wrapper bellow the #img-wrapper.
I can’t remove position: absolute (http://jsfiddle.net/9wPDy/4/) because I want to make a slider from this (that’s why my mix up with the names) and I need to be able to set the x position of each image inside their wrapper and each text inside theirs. I think this is my biggest problem. How to position them inside the container?