look now regarding the dynamic header plugin.....
lets start with fresh header .php file
remove the style we add before for the #branding (background-image) ok...
now in the header.php file find this lines of code (the beginning of the header div)>>>
<div id="header">
<div id="branding" class="clearfix">
replace it with this one>>
<div id="header">
<?php if(function_exists('dh_get_page_image_url')){ $dynamic_header_url = dh_get_page_image_url(); } ?>
<div id="branding" class="clearfix" style="background-image: <?php echo ' url(wp-content/header-images/' . $dynamic_header_url . ')'; ?>">
now the plugin will set the images as a background image to the branding div ... all you need then is to work on styling the header and branding div (remove its background color and set size ,,,,etc )..
just try....