Upon further review, after comparing the template files for tableau and the template default file for tpl_account_history_info_default.php, I found that the code for displaying the download links is missing in the tableau file. The quick fix would be to delete the tableau template file and let ZC fall back on the template default, or you could write that code block into the tableau tpl_account_history_info_default.php file.

This is the code block that is missing from the file:
Code:
/**
 * Used to display any downloads associated with the cutomers account
 */
  if (DOWNLOAD_ENABLED == 'true') require($template->get_template_dir('tpl_modules_downloads.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_modules_downloads.php');