Java Applet not loading in Safari

Hi folks.
I just noticed a problem with Safari on my Macbook Pro. I'm trying to use Keepvid to download videos from Youtube but it no longer works.
I load then link into Keepvid and then get the message "Java Applet Loading..". Except that it remains stuck like this forever and it does not work at all.
How to fix this please?


I have exactly the same problem.
(my config is
windows Xp Profesional
jre 1.4.1 03
I'm also using zonealarm as a firewall.
any Ideas?