Memcache lifetime

Looking around this problem i can't understand why it doesn't validate lifetime.

Testing with this code, also tries different values of lifetime like 1, etc:

        var_dump($cacheData->exists($cacheKey, 0)); // true
        $widgets = $cacheData->get($cacheKey, 0);

        if ($widgets === null){
            $widgets = Content::find(array(
                "page_id = '{$this->id}'",
                "order" => "widget_order",
            ));

            $cacheData->save($cacheKey, serialize($widgets), 0);
        }
        else{
            $widgets = unserialize($widgets);
        }

P.S. APC also has this problem.... only FIlebased cache works well...