zum email-check
in der datei:
include/contents/user/regist.php
ab zeile 43 den 
    
    $ch_name = false;
    $xname = escape_nickname($name);
    if (!empty($name) AND $xname == $name AND 0 == db_result(db_query("SELECT COUNT(*) FROM prefix_user WHERE name = BINARY '".$name."'"),0)) {
      $ch_name = true;
    }
    
    if ( empty($name) OR empty($email) OR $name != $xname OR $ch_name == false ) {
      $title = $allgAr['title'].' :: Users :: Registrieren :: Step 2 von 3';
      $hmenu  = $extented_forum_menu.'<a class="smalfont" href="?user">User</a><b> » </b><a class="smalfont" href="?user-regist">Registrieren</a><b> » </b>Step 2 von 3'.$extented_forum_menu_sufix;
      $design = new design ( $title , $hmenu, 1);
	    $design->header();
		  if (empty($name) OR empty($email)) {
		    $fehler = $lang['yourdata'];
		  } elseif ($name != $xname) {
        $fehler = $lang['wrongnickname'];
      } elseif ($ch_name == false) {
		    $fehler = $lang['namealreadyinuse'];
		  }
durch 
    
    #username prüfen
    $ch_name = false;
    $xname = escape_nickname($name);
    if (!empty($name) AND $xname == $name AND 0 == db_result(db_query("SELECT COUNT(*) FROM prefix_user WHERE name = BINARY '".$name."'"),0)) {
      $ch_name = true;
    }
    #email-addy prüfen
    $ch_email = false;
    $xemail = escape($_POST['email'],'string');
    if (!empty($email) AND $xemail == $email AND 0 == db_result(db_query("SELECT COUNT(*) FROM prefix_user WHERE email = BINARY '".$email."'"),0)) {
      $ch_email = true;
    }
    
    if ( empty($name) OR empty($email) OR $name != $xname OR $email != $xemail OR $ch_name == false OR $ch_email == false ) {
      $title = $allgAr['title'].' :: Users :: Registrieren :: Step 2 von 3';
      $hmenu  = $extented_forum_menu.'<a class="smalfont" href="?user">User</a><b> » </b><a class="smalfont" href="?user-regist">Registrieren</a><b> » </b>Step 2 von 3'.$extented_forum_menu_sufix;
      $design = new design ( $title , $hmenu, 1);
	    $design->header();
		  if (empty($name) OR empty($email)) {
		    $fehler = $lang['yourdata'];
		  } elseif ($name != $xname) {
        $fehler = $lang['wrongnickname'];
      } elseif ($ch_name == false) {
		    $fehler = $lang['namealreadyinuse'];
		  } elseif ($email != $xemail) {
        $fehler = 'eMail-Adresse inkorrekt';
      } elseif ($ch_email == false) {
		    $fehler = 'eMail-Adresse ungültig, da schon verwendet';
		  }
ersetzen, dann prüft er auch die emails