drupal_add_css not funtioning or functioning differently

When I upgraded to Drupal 6.4 the function drupal_add_css ceased to function as it had in Drupal 6.0. It no longer placed a CSS reference in the form page. Code snippet below.

function dvdtracker_form(&$node) {

$css = drupal_add_css('/modules/dvdtracker/dvdtracker_edit.css');

$type = node_get_types('type', $node);