swap images and rollover issues

I have a feeling there may be no good solution but if anyone has any advice
on the best way to do this I would appreciate it!

I have a menu area for "services" on a site for adoption. Initially I want
it to be childrens' drawings under the "services" tab, and when you roll
over, it will reveal the submenus (frame2). As you scroll over each submenu,
it reveals frame 3, which makes it underlined.

I've achieved this with disjoint and regular swap image; but as your cursor
goes between each slice it reveals the childrens images. Is there a way to
eliminate that? I tried hotspots that overlapped but it didn't seem to fix
it.

Here's a link: www.copelandcasati.com/test/concept1_5.htm

Thanks for any advice!