Call to undefined function geodir_is_page() by Geo 1280 Theme

When following a user activation link (wp-activate.php) the following error is generated.

PHP Fatal error: Uncaught Error: Call to undefined function geodir_is_page() in /wp-content/themes/geodir_geo-1280/functions.php:183

Checking if the function exists first allows the user activation process to continue.
To fix, I edited geodir_geo-1280/functions.php as follows:

add_filter('body_class', 'geo1280_body_class');
function geo1280_body_class( $classes ) {
	if(function_exists('geodir_is_page')){
          if (geodir_is_page('location') ) {
     		$classes[] = 'geo1280-location';
     	  }
	}
	return $classes;
}