Errors on user registration

This is the same problem as http://drupal.org/node/72217 .
When a user registers on our site, they are getting that MySQL error.

Due to the skypesupport_user function, $account->roles has not values when user registration.
So, I fixed that as follow:

/**
 * Implementation of hook_user()
 */
function skypesupport_user($op, &$edit, &$account, $category = NULL) {
  global $user;
  
  //$access = user_access('provide skype support', $account);

  switch($op) {
    // handle permissions
    case 'form':
    $access = user_access('provide skype support', $account);
    $users = variable_get('skypesupport_users', NULL);
    $skype = skypesupport_check_user($account, true);
    if ($access) {
      if (!empty($users)) {
        if (!$skype) {
          $users[] = $account->uid;
          variable_set('skypesupport_users', $users);
        }
      } else {
        variable_set('skypesupport_users', array($account->uid));
      }
    }
    break;

The question disappears.