If you put a user defined .css
<webuijsf:link id="link2" url="/resources/mystyle.css"/>

with an url() inside

.menuh_over{
   background: transparent url(horover.png) center center repeat-x;
}

The generated image path is not right because it doesn't include the context path and the "faces" folder. Mozilla
Firefox retrieves the image, but not IE 6. If you put the images in the main folder but the stylesheet is inside the
resources folder, it doesn't work either.

Workaround:
include the images inside a <style> section in each page header and put images in the root folder. Possibly you can get
the same if you put the stylesheet as a separate file in the root folder with the images.