Downloaded and installed. There is a problem with the SQL code that looks up possible matches. The table names are not using any TABLE_PREFIX.
I have added them to overcome this issue. You might want to update the code on here.
Code:
// lookup possible imposter matches
$imposter = $db->query_read("
SELECT imposter_lookup.userid, username FROM " . TABLE_PREFIX . "imposter_lookup
JOIN " . TABLE_PREFIX . "user ON " . TABLE_PREFIX . "user.userid = " . TABLE_PREFIX . "imposter_lookup.userid
WHERE soundex_value = '" . $soundex . "' OR metaphone_value = '" . $metaphone . "'
");
Cheers
Bruce