Hmm...I'm not sure how dropdown menus like that could work anyway. Even if you do have a delay, it seems like you'll still have the same problem...that being that, when you hover over a 2nd item, the items you're hovering over will all shift and you'll be hovering over something else.
Can you try to make them more like this:
http://pfirsichmelba.de/artikel-scri...orizontal.html
The submenu is beside the main items instead of underneath?