Index: gcg.module
===================================================================
--- gcg.module	(revision 301)
+++ gcg.module	(working copy)
@@ -278,14 +278,14 @@
     $privlevels = _gcg_privacy_levels();
     form_error($form['privacy'], t('You should provide a higher privacy. Required level is %level', array('%level' => $privlevels[$form['#gcg_required_privacy']])));
   }
-  if (isset($form['#value']['latitude'])) {
+  if ($form['#value']['latitude'] != '') {
     if (!is_numeric($form['#value']['latitude'])) {
       form_error($form['latitude'], t('The Latitude must be a number.'));
     } else if ($form['#value']['latitude'] < -90 || $form['#value']['latitude'] > 90) {
       form_error($form['latitude'], t('The Latitude must be between -90&deg; and 90&deg;'));
     }
   }
-  if (isset($form['#value']['longitude'])) {
+  if ($form['#value']['longitude'] != '') {
     if (!is_numeric($form['#value']['longitude'])) {
       form_error($form['longitude'], t('The Longitude must be a number.'));
     } else if ($form['#value']['longitude'] < -180 || $form['#value']['longitude'] > 180) {