i also use joomla and had the same issue, and i had just re-installed everything the day before yesterday because of a database problem where it was incorrect username, password or access level for the backend, but when i checked the table it was fine... but i had forewarning because of that, as i backed up my tables and exported them to my database, so thankfully i still have all of my content and just need to create the user and database... i could create all the tables directly in phpmyadmin, but i'm certainly going to set up a cron job to back them up like once a week just to be on the safe side, i mean i'd rather lose a week's worth of content tops than lose everything all over again