I was just about to reply, I found a solution to make it work, but I'd be curious as to why it fixes it. I see in your code you have the standard DOCTYPE excluded...is there are reason why this could be breaking it?
I found that simply removing this line from my page fixes everything.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
if you add that to your page code it will cause it do to funny things. Any idea's why it causes issues?
Thanks