It seems that the firefox download page is having some (more) troubles. Ever since I got the first link I kept seeing the Firefox 2 download version. Eventually I managed to download the file but looking back a few minutes ago, the page had again reverted to Firefox 2.
I don’t know if anyone else has the same problem, but just in case you can’t find the download link, here a direct link to the file for the English Gnu/Linux and Windows versions. Here’s the link to all the versions as well.