Help with Javascript visibility for navigation menu

Guys and gals:

I recently finished up the new website for the company i work for, and I’m having an issue where upon loading the page, the navigation menu is visible on the left side (while the initial code is building the menu) before the page fully loads…kind of hard to explain but you’ll see what i’m talking about if you go to the page. here’s the URL:

Is there a way to make the DIV’s invisible upon page load or some other method to fix this problem?

And before any of you ask, i’m using a modified version of this tutorial code for the menu, and yes, I plan to pay the author some cash for use of his code.

thanks for any help!