url style signature links are not supported by this hack and have never been offically supported. The version 1.x series of the hack used

.
Whilst the current 2.0 series uses [sig=<imageid>], naturally the installation script automatically converts old style

tags into new style [sig] tags.
The fragment below should when placed in a seperate file covert all existing [url] style links into signature links.
PHP Code:
<?php
error_reporting(7);
require ("./global.php");
$searcharray = array(
"/(\[url\]".$bburl."sig.php\?imageid\=)(.*)(\[\/url\])/esiU",
"/(\[url\]".$bburl."sig.php\?id\=)(.*)(\[\/url\])/esiU"
);
$replacearray = array(
"'[sig=\\2]'",
"'[sig=\\2]'",
);
$signatures = $DB_site->query("SELECT signature, userid FROM user");
while ($signature = $DB_site->fetch_array($signatures)) {
$newsignature=preg_replace($searcharray, $replacearray, $signature[signature]);
if ($signature[signature]!=$newsignature) {
$DB_site->query("UPDATE user SET signature='$newsignature' WHERE userid=$signature[userid]");
}
}
?>