#I tag a file like this:

my $exifTool = new Image::ExifTool;
$exifTool->ExtractInfo($image);
$exifTool->SetNewValue('XMP:Headline' => "heisannheisann");
$exifTool->WriteInfo($image);


##</code><code>##

http://ns.adobe.com/xap/1.0/
<?xpacket begin='
' id='W5M0MpCehiHzreSzNTczkc9d'?>
<x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='Image::ExifTool 7.89'>
<rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
 <rdf:Description rdf:about=''
  xmlns:photoshop='http://ns.adobe.com/photoshop/1.0/'>
  <photoshop:Headline>heisannheisann</photoshop:Headline>
 </rdf:Description>
</rdf:RDF>
</x:xmpmeta>
<?xpacket end='w'?>


-- but the exiv2 tool says:

$ exiv2 -p x Vannliljer.jpg
Vannliljer.jpg: No XMP data found in the file


When i do the same thing on a linux box, I get this:

$ exiv2 -p x tmp.jpg
Xmp.photoshop.Headline                       XmpText    14  heisannheisann


$http://ns.adobe.com/xap/1.0/
<?xpacket begin='
' id='W5M0MpCehiHzreSzNTczkc9d'?>
<x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='Image::ExifTool 7.30'>
<rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
 <rdf:Description rdf:about=''
  xmlns:photoshop='http://ns.adobe.com/photoshop/1.0/'>
  <photoshop:Headline>heisannheisann</photoshop:Headline>
 </rdf:Description>
</rdf:RDF>
</x:xmpmeta>