Render QWebPage in thread

Hi, I have a bunch of html pages that I want to render in separate threads. I looked at the documentation and found that QWebPage is a QObject, so it shouldn't generate a "cannot paint qwidget outside gui thread" warning.
But when I create the QWebpage object, I get the error, and the reason seams to be an internal class "RenderThemeQt", which creates a QPushButton.
I don't need any pushbutton because I wanted to use the QWebpage only to render to an image, so is there any way to do this?
I have already tried QTextDocument. This would work, but is a little limited in its HTML subset.

Ginsengelf

PS: Qt 4.7