jquery drop down menu

jquery drop down menu

I'm trying to develop a jquery driven drop down menu using the css-sprites technique but I'm a js newbie.

I managed to get the headlink rollovers working OK but the drop down menu rollovers are all over the place.

I've been at this for days now and read every tutorial I can find - you can see the commented out script of various earlier attempts! Can anyone tell where I'm going wrong?

Link to problem menu:

http://www.richardbarnfather.co.uk/navb ... avbar.html