With less than a minute of testing, this seems to work perfectly:

Code:
  if ($current_page_base == 'index') {
  require($template->get_template_dir('tpl_header.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/tpl_header.php'); }

  else {
  require($template->get_template_dir('tpl_header2.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/tpl_header2.php'); }?>
PROBLEM SOLVED! (or so I hope )