It isnt Java it is Javascript.
Map function requires Javascript and a compatible browser.
Which means that one of your extensions is blocking the Javascript for the page to operate correctly. I have the same issue in Opera as i use several JS to block certain items. Which also blocks it on that page as well.
But it operates fine in Safari, Chrome and IE. Javascript and Sun Java are different. You will have to find out which extensions is doing it. Make sure you have the site allowed through NoScript as well.