Fist off, most people won't see the page as you intended because Nosfer is not a standard OS font and unless people download it then they will just see plain roman text.
Your code is valid, but it appears it has to do with the absolute positioning. Absolute positioned elements break the flow of the document and must be positioned according to their outer container. You have Maincontent and menucontent right next to each other and menu content has a higher z-index. Then you are positioning the menu by using padding to the top. What you end up with is that layer overlapping the maincontent and making it inaccessible. Think of it as a window with a manufacturer's sticker on the bottom. What you are seeing is the label on the outside of the window and the layer beneath it.
You can do one of two things. First is remove the absolute positioning since the areas in this container seem to be positioned relative to one another, or change the positioning of the menucontent by positioning it absolutely with position elements defined, such as "bottom: 0;" to place it at the bottom as opposed to positioning it with padding.
Thanks for the explanation. The sticker analogy was very helpful. It's working now. I knew about the problem with nosfer, but the boss doesn't care.... "Pick your battles." Is my motto...