Since white is the default color for anything not specified it might be nowhere to be found, but I can't really understand what you are speaking of. I just hit the skins site and blocked images, and don't see any white area under the headers section. Have you removed or added any widgets? Modified the .php files in the skin perhaps?

That's right. It's just like a default colour because it loads the proper colour within a couple of seconds. But I've been using the skin for a while and have made quite a few changes - too many to recall - both to the php files and widgets. Can you think of any particular alteration that might have caused it?
Other than that all I can do is start again with a fresh skin and make all the necessary changes checking each time.