Hi again, definitely, At work the link was not working neither with Firefox 3.5.3 nor Google Chrome 2.0.172.43, after cleaning everything at the two browsers.
Nevertheless I have activated my web developer extension, and after loading one of the document page, I have cleared the errors with the WD options, and now everything works fine in Firefox.
Kind of weird, but I write down here so that people with my same problems could have a solution.