function remove($key, $layer = 'user', $channel = null)
    {
        if ($channel === null) {
            $channel = $this->getDefaultChannel();
        }

        if ($channel !== 'pear.php.net') {
            if (isset($this->configuration[$layer]['__channels'][$channel][$key])) {
                unset($this->configuration[$layer]['__channels'][$channel][$key]);
                return true;
            }
        }

        if (isset($this->configuration[$layer][$key])) {
            unset($this->configuration[$layer][$key]);
            return true;
        }

        return false;
    }