Firefox 3.5 no longer offers the option to export your saved passwords. There was not a clear answer online as to how you were supposed to import your passwords now if your machine crashed and you are recovering from a backup.
Here is how
In your old Firefox profile copy the signons3.txt and key3.db file to your current firefox profile (make sure Firefox is not running) and replace the old files. You should also delete the signons.sqlite file before restarting Firefox. That should do it, if you have trouble leave a comment below.