Description:
------------
I have singleton class and inside some protected variables.
In one function I have test check for existing of variables.
 All variables are tested OK except one with name: '_banners'.


Test script:
---------------
My test code is like this: 
Class Variables {
...
protected static $_banners=array();
protected static $instance = null;
protected function __clone() {}
protected static function getInstance($reInit=false)
    {
        if(self::$instance==null) { self::$instance = new self(); }
        if($reInit) {self::$instance = new self();}
        return self::$instance;
    }
public static function setVar($name='',$value='') {
if(!isset(self::${$name})) {return false;}
self::${$name}=$value;
return true;
}
}
Variable::setVar('_offline'); -> return true-> OK
Variable::setVar('_banners'); -> return false-> BAD

Expected result:
----------------
Expected result is return true .

Actual result:
--------------
Now function for return false for variable name "_banners"