Bad languageid and timezone set for users created by DrupalvB

After i installed vbulletin and added a new language (Arabic language) and set it to be the default one, i discovered that if i register and then login the layout goes back to the English layout which is wrong. After searching here and there i noticed that the languageid is hard coded so every time it is set to 1 (English language).
What i did so that i added these lines of code:

// To change the languageid, $languageid=2 means Arabic language, $languageid=1 means English language.
$languageid = 2;
if(isset($_SESSION['language'])){
  if('en' == $_SESSION['language']){
    $languageid = 1;
  }
}

// Set up the insertion query.

Then i modified the query to be:

$result = drupalvb_db_query("INSERT INTO {user} (username, usergroupid, password, passworddate, usertitle, email, salt, showvbcode, languageid, timezoneoffset, posts, joindate, lastvisit, lastactivity, options) VALUES ('%s', '%s', '%s', '%s', '%s', '%s', '%s', 1, %d, '%s', 0, '%s', '%s', '%s', '%s')", $edit['name'], $usergroupid, $passhash, $passdate, $usertitle, $edit['mail'], $salt, $languageid, $timezone, $joindate, time(), time(), $options);

instead of :

$result = drupalvb_db_query("INSERT INTO {user} (username, usergroupid, password, passworddate, usertitle, email, salt, showvbcode, languageid, timezoneoffset, posts, joindate, lastvisit, lastactivity, options) VALUES ('%s', '%s', '%s', '%s', '%s', '%s', '%s', 1, 1, '%s', 0, '%s', '%s', '%s', '%s')", $edit['name'], $usergroupid, $passhash, $passdate, $usertitle, $edit['mail'], $salt, $timezone, $joindate, time(), time(), $options);