Error 0x80004003 in dhtmlxwindows.js using FireFox3

Using the following code works fine in IE6 but does not in FF3. The error-message in Firebug is:

uncaught exception: [Exception… “Component returned failure code: 0x80004003 (NS_ERROR_INVALID_POINTER) [nsIDOMHTMLDivElement.appendChild]” nsresult: “0x80004003 (NS_ERROR_INVALID_POINTER)” location: “JS frame :: file:///C:/080_Programming/codebase/dhtmlxwindows.js :: anonymous :: line 87” data: no]

Some text

change StatusText

change Accordion

select AccordionNode

Coud you please provide completed demo?