Inside your <header>, you have the form, and then you have two absolute positioned elements. The nav, and #title. The nav is put down, so that's not interfering. However, the title by default, is at the top of the header. It's overlapping the form.
What do you want linked? With the anchor? Do you want the entire header to be a link? If that's the case, just give this. It'll stack on top.