Paul when you mentioned a gradient I was scratching my head, then I had a look in IE and Eureka!
firefox doesn't show the clickpop_towers_web.jpg at all. On to new problems!

What if...

You combine the two background images: the gradient and the tower, make it 1280 pixels wide total and stick it in the body tag with bottom left no-repeat properties. Then the other divs can have the blue color #153F6F as their background color.