intanto aggiungi il doctype

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="it" xml:lang="it">

poi cambia questa regola

#menu{ position: relative; top:140px; margin-left:10px; list-style-type: none; height: auto; overflow: hidden; width: 194px; border: 1px solid red; }


et voilà
Ciao