Incompatibility with the subpathauto module

I am using the pathauto module to alias the content paths of the nodes. The pattern for the Page paths is e.g. [node:title] or mysubfolder/[node:title]. So the path of the node is now www.mysite.com/nodetitle instead of www.mysite.com/node/nid.

But this also means, that the path for the edit-tab is now www.mysite.com/nodetitle/edit instead of www.mysite.com/node/nid/edit. And www.mysite.com/nodetitle/edit results a 404-error.

The same is true for other tabs in the node, used by other modules (in my case the feeds-module with the tab 'log' and the webform-module with the tabs 'webform' and 'webform-results'.

To get this working again I extended the function fast_404_validate_path_sql() in fast_404.inc with the following lines:

$admin_pages = array('edit', 'log', 'webform', 'webform-results', 'delete');
// Check tab with subfolder (www.mysite.com/subject/mynode/edit)
if (isset($path_parts[2])) {
  if (in_array($path_parts[2], $admin_pages) == TRUE) {
    $node_alias = $path_parts[0].'/'.$path_parts[1];
  }
}
// Check tab without subfolder (www.mysite.com/mynode/edit)
elseif (isset($path_parts[1])) {
  if (in_array($path_parts[1], $admin_pages) == TRUE) {
    $node_alias = $path_parts[0];
  }
}
// Check if if node_alias exists 
if (isset($node_alias)) {
  $node_alias_stmt = $pdo->prepare("SELECT alias FROM url_alias WHERE alias = :alias");
  $node_alias_stmt->execute(array(':alias' => $node_alias));
  if ($node_alias_stmt->fetch()) {
    return TRUE;
  }
}