Theme username as content profile first name

Attempted code from http://drupal.org/node/316009#comment-1189756 into theme_username but crashed my site.
Can't seen to find any information to set the theme_username to always be the content profile first name field.
Any suggestions?

  $firstname = $content_profile->get_variable('uprofile', 'field_firstname');
  $firstname = $firstname[0]['value'];
  print $firstname;

I'm not sure if this is the best way to do it, I got this code originally from someone else on this site, but I can't seem to find it at the moment. Modified to display the title of the content profile as a link to the user profile:

This seems to work for v1.0 (not dev). All I need to figure out now is how to modify the user profile page title.

function phptemplate_username($object, $link = TRUE) {
  if ( $object->uid && function_exists('content_profile_load') ) {
    $content_profile = content_profile_load('profile', $object->uid);
  }

  if ( $content_profile ) {
    $name = $content_profile->title;

    if ( $link && user_access('access user profiles')) {
      return l($name, 'user/'. $object->uid, array('title' => t('View user profile.')));
    }
    else {
      return check_plain($name);
    }
  }

  // Profile field not set, default to standard behaviour
  if ($object->uid && $object->name) {
    // Shorten the name when it is too long or it will break many tables.
    if (drupal_strlen($object->name) > 20) {
      $name = drupal_substr($object->name, 0, 15) .'...';
    }
    else {
      $name = $object->name;
    }

    if ( $link && user_access('access user profiles')) {
      $output = l($name, 'user/'. $object->uid, array('title' => t('View user profile.')));
    }
    else {
      $output = check_plain($name);
    }
  }
  else if ($object->name) {
    // Sometimes modules display content composed by people who are
    // not registered members of the site (e.g. mailing list or news
    // aggregator modules). This clause enables modules to display
    // the true author of the content.
    if ($object->homepage) {
      $output = l($object->name, $object->homepage);
    }
    else {
      $output = check_plain($object->name);
    }

    $output .= ' ('. t('not verified') .')';
  }
  else {
    $output = variable_get('anonymous', 'Anonymous');
  }

  return $output;
}

subscribing - would anyone familiar with programming be able to comment on code at #4?
Thanks!

Try this one here, it might be a solution for your problem: http://drupal.org/node/285367

One suggestion for #4 - implement cache_get and cache_set. Otherwise you are running a node_load constantly to pull up the profile fields.

This is lovely, but it also seems to have caused an issue in forums for me. A valid author can't be found.

Seems odd since this is a theme layer change not effecting usernames on user objects.

What about profile_load_profile function?

I've succeeded with the following code in template.php without activating Content Profile module:

function themename_username($object) {
  if ( $object->uid && function_exists('profile_load_profile') ) {
    profile_load_profile(&$object);
  }
  
  if ( !empty($object->profile_name) ) {
    $name = $object->profile_name;
    if (user_access('access user profiles')) {
      return l($name, 'user/'. $object->uid, array('title' => t('View user profile.')));
    }
    else {
      return check_plain($name);
    }
  }

  // Profile field not set, default to standard behaviour
... %rest of the function, copied from theme.inc%