Broken menu in Studio theme when there are sub-pages

On every page except for the home page, there is a problem in the display of the sub-pages when scrolling over the various pages under a top-category. The sub-pages are displayed several px to the right of it's parent's name. As a result, when the user tries to select one of these sub-pages, the menu disappears because their mouse must pass through a space that is not part of the menu (so the page thinks the user moved their mouse off of the menu, causing it to go away).