I haven't installed this, just looking at the code, and I noticed this in Ragtek_TBSBB_DW:
PHP:
protected function _postSave()
{
parent::_postSave();
if ($this->isChanged('dob_day') || $this->isChanged('dob_month') ||
$this->isChanged('dob_year') || $this->isChangeD('show_dob_date', 'xf_user_option')) { // isChangeD != isChanged
Ragtek_TBSBB_Cron::setTodaysBirthdays();
}
}