I would suggest you reinstall the database. You would then reinstall the photopost files and run install.php to get things working make sure to use the same table prefix as the old tables this will not delete old data and then run upgrade after install to update tables etc
You should then have a working photopost. Take note to do this you will need a working backup of the data directory and database at minimum. You also need to reset permissions accordingly as well like a new install.