On the main menu, mouse over “Donate” - the 4th sub-menu item is going behind div #main. The second issue is, that same sub-menu has a child menu (with the same issue) and is also being cut off by the constraints of the wrapper.
I cannot get to your CSS style sheet and the snippet you provided is not enough to let me see what you are actually doing. remember that code interacts with ALL other code so anything you do affects everything you do.
At them moment tho , am guessing, that your sub menu is in fact NOT going behind your main, but getting cut off from the display.
I am guessing section.row and/or section.wrapper probably have overflow:hidden; applied to them which is causing your sub menus to be cropped. I would use a different clearing method for these two specific elements to fix this problem.
Removing overflow:hidden from row gives me the child menu: (01.jpg), removing overflow:hidden from wrapper gives me the child menu: (02.jpg). How do I remedy this?
As this class is probably applied to other things in your cod you have painted yourself in a corner here, w/o seeing all your code…I would suggest adding an ID. this is kinda heavy handed , but it will make sure we override that code for those specific elements.