evaluateXPathExpression attributes of element with namespace

I have an xml like this (reduced example):

<root xmlns:test="http://ns.test.com/test/2.0">
    <test:master>
        <test:graphic control="ABC"/>
        <test:textframe>TEXT</test:textframe> 
    </test:master>

    <test:master>
        <test:graphic control="XYZ"/>
        <test:textframe>TEXT</test:textframe> 
    </test:master>
</root>

As you can see the "test:graphic" element contains a "control" attribute.

I'd like to get all elements with a "control" attribute of the first "master" element with evaluateXPathExpression.

WITHOUT namespaces this code works:

var root = doc.xmlElements[0]; // doc is the current document
var xmlElements = root.xmlElements[0].evaluateXPathExpression("//*[@control]");
--> 1 result

But WITH namespaces it doesn't:

var namespaces = new Array(new Array("test","http://ns.test.com/test/2.0"));
var root = doc.xmlElements[0]; // doc is the current document
var xmlElements = root.xmlElements[0].evaluateXPathExpression("//*[@control]",namespaces);
--> 0 results

Althoug it works WITH namespaces on the root element (not on the first "master" like above) 

var namespaces = new Array(new Array("test","http://ns.test.com/test/2.0"));
var root = doc.xmlElements[0]; // doc is the current document
var xmlElements = root.evaluateXPathExpression("//*[@control]",namespaces); //
--> 2 results

So i was wondering what am i doing wrong and how adress only a specific "master" element.