Firefox: HTML DOM fails if a local XSL transformation does not specify xsl:output

This nasty beast took me a while to figure out: if you do local XSL transforms in Firefox 1.5 and don't have the xsl:output directive in your main XSL stylesheet, HTML-specific DOM calls might not work.

The results are weird: for example, whatever is produced with the XSL transformation behaves like a HTML DOM object, but if you create a new element, it lacks HTML-specific DOM calls.

And the obvious solution: make sure you're always including ...

<xsl:output method="html" encoding="utf-8"
doctype-public="-//W3C//DTD XHTML 1.0 Transitional//EN"
doctype-system="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"/>

... in your XSL stylesheet.