I'm no pro but I see possible problems here (pasting from the "view source" function of the validator site): # <ul> # <!-- START PAGES LIST --> # <h2>Pages</h2> # <ul> Code (markup): Here you have UL tags started, but you don't have any LI tags inside. You're making an unordered list without any list content. Also in that above past you don't have a closing UL tag. Lines 152-155 look ok to me (you have both an opening/closing UL as well as some LIs). As for line #235, you just have a lone "</ul>" tag. There's no opening UL tag. If you scroll up above all that javascript you'll see you already closed the UL tag.