Although his URL means “rocket science”, his site seems to be down so I wouldn’t expect an updated version too soon.

Luckily a nice guy named Daniel Olivares has created a new version which runs on FireFox 3.5.

If you own one or more sites the little number that appears in the FireFox status bar is an addiction. The Google Toolbar offers the same, but of course you don’t want the whole package and that’s why this add-on is so popular.

Edit: at the time of writing this new version worked, but it seems like it no longer does. Neither does the one downloadable on the official plugins site (although some users report it does, e.g. with firefox 3.7).

While there seem to be different causes, if you’re on Windows and using AVG, the file that contains cookies may be locked by AVG for some reason. Deleting that file or disabling AVG to scan cookies may help.

FireFox saves cookie information on Windows in:

[DRIVE]:\Documents and Settings\[USER]\Application Data\
Mozilla\Firefox\Profiles

The file is named cookies.sqlite.

If you delete it however, you’ll have to check quite a few “remember me” boxes in the near future.