DOMWrite an HTMLDocument

Hey Barracuda wizards!

I'm updating an application from Barracuda 0.something to Barracuda 1.2 
and I got stuck on this:

--
java.lang.NullPointerException
	at 
org.enhydra.xml.io.BaseDOMFormatter.getEncoding(BaseDOMFormatter.java:326)
	at org.enhydra.xml.io.BaseDOMFormatter.(BaseDOMFormatter.java:374)
	at org.enhydra.xml.io.HTMLFormatter.(HTMLFormatter.java:99)
	at org.enhydra.xml.io.DOMFormatter.getFormatter(DOMFormatter.java:156)
	at org.enhydra.xml.io.DOMFormatter.write(DOMFormatter.java:192)
	at 
org.enhydra.barracuda.core.util.dom.DefaultDOMWriter.write(DefaultDOMWriter.java:181)
	at 
org.enhydra.barracuda.core.util.dom.DefaultDOMWriter.write(DefaultDOMWriter.java:146)
	at 
lsb.presentation.screens.WizardScreen$RenderTabPreviewHandler.handleViewEvent(WizardScreen.java:336)
--

when writing an HTMLDocument with DefaultDOMWriter.

Do you guys have an idea what it could be? The reduced testcase is:

HTMLDocument themeDoc = 
org.enhydra.xml.xmlc.html.HTMLDocumentFactory.createBasicDocument();
new DefaultDOMWriter().write(themeDoc, context.getResponse());


Cheers,
Roger.