I am querying flickr with the following request:

view-source:http://www.flickr.com/services/rest/?method=flickr.photos.search&api_key=MY_KEY&text=cork&per_page=12&&format=rest

if I put the above url in the browser I get the following as I would expect:

<rsp stat="ok"> 
<photos page="1" pages="22661" perpage="12" total="271924"> 
    <photo id="4587565363" owner="46277999@N05" secret="717118838d" server="4029" farm="5" title="06052010(001)" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587466773" owner="25901874@N06" secret="32c5a1a57f" server="4002" farm="5" title="black wine cork 2 BW" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4588084730" owner="25901874@N06" secret="b27eef5635" server="4032" farm="5" title="black wine cork 2" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587457789" owner="43115275@N00" secret="ae0daa0ab6" server="4034" farm="5" title="Matthew" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587443837" owner="49967920@N07" secret="2b4c1a58de" server="4066" farm="5" title="Two car garage" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4588050906" owner="45827769@N06" secret="72de138f7e" server="4067" farm="5" title="Dabie Mountains, Central China" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587979300" owner="36531359@N00" secret="e5f8b30734" server="3299" farm="4" title="stroll" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587304769" owner="7904649@N02" secret="995062f550" server="4034" farm="5" title="IMG_4325" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587306827" owner="7904649@N02" secret="b92d7ff916" server="4050" farm="5" title="IMG_4329" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587311657" owner="7904649@N02" secret="bb1b34ccf8" server="4053" farm="5" title="IMG_4336" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587933110" owner="7904649@N02" secret="f733b1d482" server="3300" farm="4" title="IMG_4334" ispublic="1" isfriend="0" isfamily="0" /> 
    <photo id="4587930650" owner="7904649@N02" secret="9bc202b3ed" server="4018" farm="5" title="IMG_4331" ispublic="1" isfriend="0" isfamily="0" /> 
</photos> 
</rsp>

Now I've got something very simple PHP to query the exact same url, called from javascript through AJAX - it all works as I can see putting a breakpoint in my javascript function that handles the response:

function HandleResponse(response)
{
  document.getElementById('ResponseDiv').innerHTML = response;
} 

Looking at response value in the snippet above I see what I expect (xml formed as above) - then the strangest thing happens: when I inspect the DOM instead of having photo elements all as children of photos they're all nested within each other.

What amI missing - How is this possible in light of the fact that the response string is definitely formed as I would expect it to be?