QDomDocument does not parse certain nodes correctly

I have a xml file with contents:
<xml>
...
<url>http://www.stephenfry.com/?feed=podcast&format=audio</url>
...
</xml>

This is then read into QFile and set as content into a QDomDocument:
QDomDocument *doc = new QDomDocument("document");
doc->setContent(&file, false);
qDebug() << doc->toString();

toString() returns:
"<xml>
...
<url/>
...
</xml>"

If I change xml file's <url> content to:
<url>http://www.stephenfry.com/?feed=podcast</url>

-> this is parsed correctly.
-> "&format=audio" part somehow causes this failure?