--- includes/form.inc	2010-05-19 08:02:32.000000000 -0700
+++ includes/patched.form.inc	2010-06-27 14:22:21.000000000 -0700
@@ -682,7 +682,8 @@ function _form_validate($elements, &$for
       // A simple call to empty() will not cut it here as some fields, like
       // checkboxes, can return a valid value of '0'. Instead, check the
       // length if it's a string, and the item count if it's an array.
-      if ($elements['#required'] && (!count($elements['#value']) || (is_string($elements['#value']) && strlen(trim($elements['#value'])) == 0))) {
+      // First, let's check what kind of field this is...
+      if ($elements['#required'] && (!count($elements['#value']) || ($elements['#type'] == 'checkbox' && !$elements['#value']) || (is_string($elements['#value']) && strlen(trim($elements['#value'])) == 0))) {
         form_error($elements, $t('!name field is required.', array('!name' => $elements['#title'])));
       }