The official del.icio.us 1.1 extensions for Firefox doesn't work with the about-to-be-released Firefox 2.0. Fortunately it just takes a quick tweak to get it going:

1. Go to your Firefox profile directory and then to its extensions subdirectory.


2. Do a find for del.icio.us.jar. It should be in the chrome subdirectory of some distinctly unspellable directory.


3. Go to the directory above that chrome one. There should be a file called install.rdf.


4. Open that file in your favourite text editor. If it's the correct one it should say em:name="del.icio.us" somewhere in the file.


5. Assuming you found the correct file, change the line that reads em:maxVersion="1.5.0.*" /> so that it reads em:maxVersion="2.*" /> instead.


6. Restart Firefox 2.0 and your del.icio.us extension should be working again.

UPDATE:I've heard that at least one person wasn't able to get this workaround to work. I'm not sure why that would be; perhaps the person has an older version of the extension. I know that on my work PC I didn't get Firefox 2.0 closed down all the way the first time I tried it, so the extension was disabled. When I closed down properly it worked as expected, just like it did on the other computers I've done it on.

Also, it doesn't matter whether you do this before or after you install Firefox 2.0. You're just changing one line in a configuration file, so the only thing to make sure is that Firefox is exited fully before trying again. If your del.icio.us buttons or menu don't appear then go back to Tools\Add Ons and you'll probably see the extension is still disabled.

UPDATE:Version 1.2 of the del.icio.us extension is out now and Firefox 2.0 should update it for you. This post may still be useful for other extensions that haven't been updated, but is otherwise moot.