DavidIQ wrote: Check your config.php file. The table prefix is supposed to be set from there.
Yes, it's set correctly there:
// phpBB 2.x auto-generated config file
// Do not change anything in this file!
$dbms = 'postgres';
$dbhost = 'localhost';
$dbname = 'bboard';
$dbuser = 'www';
$dbpasswd = 'xxxxx';
$table_prefix = 'phpbb_';
I've managed to fix it now - I think there was a problem in the mod files.
I moved my old installation and reinstalled from scratch into a new database. Then I installed the mod and edited $dbname to point back to the old database.
Then it was just a matter of copying images etc from the backup copy and all is well!