I did not test the logo div method and and it does not work well as you have found! Sorry about that and also error in my CSS!
However now I have time to test it I find that you can delete the logo div and just add this line to the #page-header CSS like so...
#page-header {
width: 96%;
height: 160px;
margin: 0 auto;
padding: 0;
text-transform: lowercase;
color: white;
background: url([[pix:theme|logo]]) no-repeat left top;
}
It works perfectly!