[Andreas]

This is what I did on our board several month ago (moreless copy&paste, hope it does work)

1. Create the following phrase in phrasegroup Front-End Error Messages
   varname = sigtoomanylines
   text = Your signature can not be longer than $vboptions[maxsiglines] lines.
2. In vBulletin Options/User Profile Options create the following setting:
   varname = maxsiglines
   title = Maximum signature lines
   description = The maximum number of lines anyone can use in their signature.
   default = 4
   vBulletin Standard = No
3. In profile.php FIND
   
   PHP Code:

   if ($vboptions['maximages'] != 0)
{
  require_once('./includes/functions_bbcodeparse.php');
  $parsedsig = parse_bbcode($signature, 0, $vboptions['allowsmilies'], 1); 

   REPLACE that with
   
   PHP Code:

   if ($vboptions['maxsiglines'] != 0) {
  require_once('./includes/functions_misc.php');
  require_once('./includes/functions_bbcodeparse.php');
  $parsedsig = parse_bbcode($signature, 0, $vboptions['allowsmilies']);
  $siglines = 0;
  $siglines += fetch_character_count($parsedsig, '<br');
  $siglines += fetch_character_count($parsedsig, '<blockquote');
  $siglines += fetch_character_count($parsedsig, '<pre');
  if ($siglines > $vboptions[maxsiglines]-1) {
    $preview = 'true';
    eval('$errors[] = "' . fetch_phrase('sigtoomanylines', PHRASETYPEID_ERROR) . '";');
  }
}

if ($vboptions['maximages'] != 0)
{
  if (!$parsedsig) {
    require_once('./includes/functions_bbcodeparse.php');
    $parsedsig = parse_bbcode($signature, 0, $vboptions['allowsmilies'], 1);
  }