Hmm..this is tricky. Those dark vertical lines are actually the shadow of the container. Removing it will remove the shadow from the top all the way down to the bottom of the page, making your content area (possibly) indistinguishable from your background.
However, with some CSS trickery:
#container {
margin-top: 198px;
}
#header {
position: absolute;
left: 0;
top: 0;
}
That ought to do it.