Hi Paul-
Thanks for reaching out, and thanks for using one of our Platinum WordPress Hosting partners, DreamHost.
I took a look at your site, and I can see what you mean. When you hover over a sub-menu, it appears correct, but as soon as you click on it some JavaScript moves the menu item “behind” the main menu items on the second row below.
This behavior is a part of your theme, X Blog, and it’s tough to speculate what’s going on with that. I tried several different modifications using the z-index property of the submenu, but in any case it reacted as soon as the sub-menu item was clicked.
I’d recommend reaching out in X Blog’s Support Forum to see if they’re able to offer a solution.