I have been trying several ways to have a first level of navigation using images (with rollovers using CSS) and a second level of dropdown menus using the text.
Currently I have the first level nav with the images hiding the text with a span class that is set to display: none; in the css.
Don’t hide navigation link text using display:none. You’re effectively hiding your top level navigation from a whole range of non-graphical user agents – including Google. Use a negative text indent or negative absolute positioning instead.
You’ll may then need to reset the styling for the second level links.