nsIDocumentEncoder returning always the whole text?

Hi all,

I had some embeding code that used to work with xulrunner 1.9.2 (i.e. 
last year), but stopped working with xulrunner 2.0. The code creates an 
nsIDocumentEncoder, and uses EncodeToString() to serialise specific DOM 
elements (some DIVs) to plain text.

In xulrunner 2.0, the code somewhat works (i.e. I get a text back), but 
this text is not the DOM node I set with SetNode, but the whole 
document. The encoder flags are 0 (no flags).

Any ideas on what has changed, and what is wrong now with my code?

Regards,

George