h1#pageTitle {
margin:0;
}

¥

I fixed it by adding a 1px padding to the header. No idea why this works.

div.pageHeader {

	padding: 1px;
	margin: 0px 0px 0px 0px;
	height: 151px;
	background: url(http://www.tvcm.co.uk/b2/raven/skins/home/img/left.jpg) no-repeat #330099;
	background-position:left;
	
}

oops ¥åßßå - slipped your post. I'll try your solution cos mine seems a bit hamfisted