Multiple funtions in templates.php returns blank page?

I have installed page_title-4.7.x-1.x-dev and flatforum-4.7.x-1.x-dev. The modules were tested and work flawlessly; however both require additions to templates.php.

The problem is that the two functions work when used separately but when both are added to templates.php I get a blank page when viewing the site. Please have a look at the code below; any help will be greatly appreciated.

<?php

/*
  page_title.module addition
*/
function _phptemplate_variables($hook, $vars) {
  $vars = array();
  if ($hook == 'page') {
  	if (module_exist('page_title')) {
      $vars['head_title'] = page_title_page_get_title();
  	}
  }
  return $vars;
}



/*
  flatforum.module addition
*/
// $Id: template.php,v 1.7 2006/05/11 18:17:29 ayman Exp $
function _phptemplate_variables($hook, $vars) {
  static $is_forum;
  $variables = array();
  if (!isset($is_forum)) {
    if (arg(0) == 'node' && is_numeric(arg(1)) && arg(2) == '') {
      $nid = arg(1);
    }
    if (arg(0) == 'comment' && arg(1) == 'reply' && is_numeric(arg(2))) {
      $nid = arg(2);
    }
    if ($nid) {
      $node = node_load(array('nid' => $nid));
    }
    $is_forum = ($node && $node->type == 'forum');
    _is_forum($is_forum);
  }
  if ($is_forum) {
    switch ($hook) {
      case 'comment' :
        $variables['template_file'] = 'node-forum';
        $variables['row_class'] = _row_class();
        $variables['name'] = $vars['author'];
        $variables['userid'] = $vars['comment']->uid;
        $joined = module_invoke('flatforum', 'get_created', $vars['comment']->uid);
        $variables['joined'] = $joined ? format_date($joined, 'custom', 'Y-m-d') : '';
        $posts = module_invoke('flatforum', 'get', $vars['comment']->uid);
        $variables['posts'] = $posts ? $posts : 0;
        $variables['submitted'] = format_date($vars['comment']->timestamp);
        $subject = $vars['comment']->subject;
        $variables['title'] = empty($subject) ? '&nbsp' : $subject;
        $variables['content'] = $vars['comment']->comment;
        $variables['links'] = empty($vars['links']) ? '&nbsp' : $vars['links'];
        break;
      case 'node' :
        $variables['row_class'] = _row_class();
        $variables['userid']=$vars['node']->uid;
        $joined = module_invoke('flatforum', 'get_created', $vars['node']->uid);
        $variables['joined'] = $joined ? format_date($joined, 'custom', 'Y-m-d') : '';
        $posts = module_invoke('flatforum', 'get', $vars['node']->uid);
        $variables['posts'] = $posts ? $posts : 0;
        $variables['title'] = empty($vars['title']) ? '&nbsp' : $vars['title'];
        $variables['content'] = $vars['node']->body;
        $variables['links'] = empty($vars['links']) ? '&nbsp' : $vars['links'];
        break;
    }
  }
  return $variables;
}
function _row_class() {
  static $forum_row = TRUE;
  $forum_row = !$forum_row;
  return $forum_row ? 'odd' : 'even';
}
function _is_forum($arg = NULL) {
  static $is_forum = FALSE;
  if ($arg) {
    $is_forum = $arg;
  }
  return $is_forum;
}

I have tried to research this but I'm new to drupal and know little more than basic php. Also I'm not sure if the code should resemble the following or wether or not the ending ?> tag should be included.

<?php 
//EXISTING CODE 
?>
<?php 
//NEW CODE 
?>

or

<?php
//code from #1
//code from #2
?>

Thanks guys,
ncweb