Problems with advanced_search in trip_search module

Hi all,
Using drupal 4.6.3 on apache 1.3.27 and php 4.4 on a localhost

I have a problem when I go to advanced search - I get
warning: Invalid argument supplied for foreach() in /usr/local/apache_1.3.27/htdocs/gydgdemo/includes/tablesort.inc on line 160.

warning: Invalid argument supplied for foreach() in /usr/local/apache_1.3.27/htdocs/gydgdemo/includes/tablesort.inc on line 198.

warning: Invalid argument supplied for foreach() in /usr/local/apache_1.3.27/htdocs/gydgdemo/includes/theme.inc on line 639.

I cannot find any references to this problem, please for any advice
Vidya