I've just tested with with the same version of Firefox as you are using, 1.5.0.8.
Everything seemed to work fine for me.
You have already applied three of the four usual client-side fixes for the javascript void(0) problem:
- You have disablabled your popup blocker.
- You aren't using a web proxy. (right?)
- You have enable JavaScript.
The fourth fix is to upgrade your web browser or switch to an alternative web browser. Is this the only web site which is failing in this way for you? Have you considered FireFox 2.0, Opera, SlimBrowser, or IE?
One more thought -- you might be running a web proxy without knowing it. chello.se might be pushing your traffic automatically and transparently through a caching proxy. We set up Inktomi caches when we first setup chello.se. You might have to contact them to ask what they are doing now.