Problem modifying image gallery

I posted this at http://drupal.org/node/41259, but it's so far down the list I'm sure it will be missed so am posting it again in a new topic.

When I first asked how to modify the look of the image gallery I couldn't get it to work and ended up directly modifying image_gallery.module instead (I know it's not the drupal way). I since decided I want to use the hook that is described in the above handbook page, but when I do it goes from not looking how I want to not showing at all.

I followed the instructions, inserting the following into template.php:

<?php
/**
* Catch the theme_image_gallery function, redirect through the template api
* and point Drupal to your image_gallery.tpl.php file to determine the layout
* of your image gallery pages.
*/
  function phptemplate_image_gallery($galleries, $images) {
  // Pass to phptemplate, including translating the parameters to an associative array. The element names are the names that the variables
  // will be assigned within your template.
  /* potential need for other code to extract field info */
    return _phptemplate_callback('image_gallery', array('galleries' => $galleries, 'images' => $images));
  }
?>

Then I created image_gallery.tpl.php, copying the theming section from image_gallery.module as follows:

<?php
/**
 * Theme a gallery page
 */
  // We'll add height to keep thumbnails lined up.
  $size = _image_get_dimensions('thumbnail');
  $width = $size['width'];
  $height = $size['height'];

  $content = '';
  if (count($galleries)) {
    $content.= '<ul class="galleries">';
    foreach ($galleries as $gallery) {
      // $content .= '<li style="height : '.$height .'px">';
      if ($gallery->count)
        $content.= l(image_display($gallery->latest, 'thumbnail'), 'image/tid/'.$gallery->tid, array(), NULL, NULL, FALSE, TRUE);
      $content.= "<h3>".l($gallery->name, 'image/tid/'.$gallery->tid) . "</h3>\n";
      $content.= '<div class="description">'. check_markup($gallery->description) ."</div>\n";
      $content.= '<p class="count">' . format_plural($gallery->count, 'There is 1 image in this gallery', 'There are %count images in this gallery') . "</p>\n";
      if ($gallery->latest->changed) {
        $content.= '<p class="last">'. t('Last updated: %date', array('%date' => format_date($gallery->latest->changed))) . "</p>\n";
      }
      $content.= "</li>\n";
    }
    $content.= "</ul>\n";
  }

  if (count($images)) {
    $height += 75;
    $content.= '<ul class="images">';
    foreach ($images as $image) {
      $content .= '<li';
      if ($image->sticky) {
        $content .= ' class="sticky"';
      }
      $content .= ' style="height : '.$height .'px; width : '.$width.'px;"';
      $content .= ">\n";
      $content .= l(image_display($image, 'thumbnail'), 'node/'.$image->nid, array(), NULL, NULL, FALSE, TRUE);
      $content .= '<br />'.l($image->title, 'node/'.$image->nid);
      if (theme_get_setting('toggle_node_info_' . $image->type)) {
        $content .= '<div class="author">'. t('Posted by: %name', array('%name' => theme('username', $image))) . "</div>\n";
        if ($image->created > 0) {
          $content .= '<div class="date">'.format_date($image->created)."</div>\n";
        }
      }
      $content .= "</li>\n";
    }
    $content.= "</ul>\n";
  }

  if ($pager = theme('pager', NULL, variable_get('image_images_per_page', 6), 0)) {
    $content.= $pager;
  }

  If (count($images) + count($galleries) == 0) {
      $content.= '<p class="count">' . format_plural(0, 'There is 1 image in this gallery', 'There are %count images in this gallery') . "</p>\n";
  }

  return $content;
?>

As I said, nothing shows at all so if anyone can help or point me in the right direction it would be appreciated.