Javascript pop-up menu problem in Firefox, works fine in IE

Hi,

I'm implementing a pop up menu script that I found at:

http://simplythebest.net/scripts/DHTML_scripts/dhtml_script_94.html

It works great on my page in IE, but I cannot get the popup menu to appear in Firefox!

here is a link to my page: http://www.juxtaexposed.com/test

if you hover your mouse on the map over Iceland (the little tiny piece next to greenland!) the menu shows up in IE. but when i try to do that in firefox, I dont get the same menu, nothing pops up and there are no errors.

Thank you in advance for any help!