Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.438
diff -u -r1.438 form.inc
--- includes/form.inc	7 Mar 2010 23:14:20 -0000	1.438
+++ includes/form.inc	8 Mar 2010 16:22:08 -0000
@@ -2780,8 +2780,10 @@
  */
 function theme_form($variables) {
   $element = $variables['element'];
+  _form_set_class($element, array('form-wrapper'));
   // Anonymous div to satisfy XHTML compliance.
   $action = $element['#action'] ? 'action="' . check_url($element['#action']) . '" ' : '';
   return '<form ' . $action . ' accept-charset="UTF-8" method="' . $element['#method'] . '" id="' . $element['#id'] . '"' . drupal_attributes($element['#attributes']) . ">\n<div>" . $element['#children'] . "\n</div></form>\n";
 }