You really need to go to the developer. This extension is not on the official Mozilla Add-ons site. Please don't post annoying duplicates.

Developer site is not opening. I have downloaded this extension from the official Mozilla site. What do you mean by duplicates?

I'm afraid I can't help. It looks as if the extension has been abandoned. I did eventually find it on the AMO list - the search process let me down.. As you probably know it has not been updated since Sept 2008 and is marked as not available for Fx4.0.1.

This question, perhaps accidentally, was posted twice.

These latest posts will bring your question under notice again and someone may come up with a substitute.