whitespace between layout element layers

I've created a page template through SF admin and added 4 rows. 
The top row is a 2 column layout element acting as my header with a content block on the left side and a search box on the right.
The second row has a single layout element which has a menu (horz)
The third is a single layout element and the fourth row has a single element with a content block in it acting as a footer.

I created a page with the template.

When I view the page with FireFox everything looks good.

When I view the page with IE8 there is white space beneath each layout element.

Using Firebug I can't see any reason for the space - which appears to be about 10px.

Any way to get rid of the space?

Here's a link to the site - notice the space below the header above the menu
http://www.thinriversites.com/
Thanks!

Ron

As a general rule, I personally wouldn't style anything on the generated "sf_col" classes...becasue that means every 75%-25% layout dropped will get styled with green text and the yellowish background.  What would be more advisiable is on the parent layout of those, to set the Wrapper Css Class to somehting like .headerstyle.. whos definition is in the CSS.

I was able to remove the space with

Thanks Steve!