Header Image Background – business directory skin

Hi,
In the business directory theme, there is a background image covering the header + the HTML SLider, and I am not able to reproduce the same effect : the image only covers the background of the header.
I am using the Home Page Editor with the HTML Slider snippet, but that snippet stays right under the .header_wrapper block which is containing the image, and no “display location” solves the issue.

When I open webdevloper tools, if I move the whole HTML SLider snippet inside the .header_wrapper, I get the same effect as the demo, but this is not the right solution, because in this case I have to edit the header file and leave open the .header_wrapper DIV tag which is used also on the other pages…

What would be the clean solution for this ?