Hello, this quick mod will allow you to edit in your ADMIN (CP) The amount of lines or "Breaks" each user is allowed to have on there signature.

Find in Admin/ad_Settings.php:
$ADMIN->html .= $SKIN->add_td_row( array( "<b>Maximum length (in bytes) for user signatures</b>" ,
$SKIN->form_input( "max_sig_length", $INFO['max_sig_length'] )
) );
$ADMIN->html .= $SKIN->add_td_row( array( "<b>Number of Lines a Signature can have</b>" ,
$SKIN->form_input( "sig_max_lines", $INFO['sig_max_lines'] )
) );$this->save_config( array ( 'av_gal_cols' , "disable_ipbsize", "photo_ext", 'subs_autoprune', 'topicpage_contents', 'postpage_contents', 'allow_skins', 'max_sig_length', 'sig_allow_ibc', 'sig_allow_html','avatar_ext','avatar_url','avup_size_max','avatars_on','avatar_dims','avatar_def', 'max_location_length', 'max_interest_length', 'post_titlechange',
$this->save_config( array ( 'av_gal_cols' , "disable_ipbsize", "photo_ext", 'subs_autoprune', 'topicpage_contents', 'postpage_contents', 'allow_skins', 'max_sig_length', 'sig_max_lines', 'sig_allow_ibc', 'sig_allow_html','avatar_ext','avatar_url','avup_size_max','avatars_on','avatar_dims','avatar_def', 'max_location_length', 'max_interest_length', 'post_titlechange',
if ( $HTTP_POST_VARS['key'] != $std->return_md5_check() )
{
$std->Error( array( 'LEVEL' => 1, 'MSG' => 'del_post' ) ); }$max_lines = $ibforums->vars['sig_max_lines'];
$text = $HTTP_POST_VARS['Post'];
$text = strip_tags($text);
$text .= "\n";
$check = explode("\n", $text);
$lines = count($check);
# Error process.
if ($lines > $max_lines) {
$std->Error( array( 'LEVEL' => 1, 'MSG' => 'sig_max_lines' ) );
}$INFO['sig_max_lines'] = '0';Anywhere.