I’ve been doing some work for a website in Joomla and there appears to be one small issue. When I hover over a menu item in one of the drop downs the color or hover doesn’t select the whole item.
Do you mean on the top level links (in the main menu bar)? If so, try making the background image taller. There is a little gap under it in all browsers I checked (and as shown in logic_earth’s screen shots).