Illegal use of theme_table

I just installed trip_search and I think it is great!!

However, when I went to the advanced search I was getting an errorr "warning: Invalid argument supplied for foreach() in /var/www/cbi/drupal/includes/tablesort.inc on line 160."

I tracked it down to line 384 of trip_search.module (v. 1.30):
$group = theme('table', '', $rows);

At least in my version of theme.inc you can't pass a null string for arg 1 ($headers).

I fixed it by passing an empty array:

$blank[] = array();
	$group = theme('table', '$blank', $rows);

It seems to work. Was this left blank for a reason? Am I missing something?

Great module. Thanks.