Problem getting nsIDOMHTMLDocument from within a timer callback

[Damien O'Brien]

Hi,
I'm trying to get my hands on the nsIDOMHTMLDocument from within a timer
callback function. 
Below I've pasted in the code which I though should work but unfortunately
isn't. I get the nsIDOMWindow and nsIDOMDocument  just fine, but when I try
to get the nsIDOMHTMLDocument from the nsIDOMDocument it fails -
nsIDOMHTMLDocument is being returned as NULL. Does anyone have any ideas on
what could be wrong or another way that I can do the same thing?

Thanks,
 Damien

================
void MyMozilla::TimerCallback(nsITimer *aTimer, void *aClosure)
{
        OutputDebugString(_T("In the timer...\n"));
        nsCOMPtr<nsIWindowWatcher> 
                wwatch(do_GetService(NS_WINDOWWATCHER_CONTRACTID)); 

        nsIDOMWindow *wind = NULL; 
        wwatch->GetActiveWindow(&wind); 
        if (wind) 
        { 
                nsIDOMDocument *dom_doc  = NULL; 
                wind->GetDocument(&dom_doc); 
                if (dom_doc) 
                { 
                                nsCOMPtr<nsIDOMHTMLDocument>
                                htmlDomDocument(do_QueryInterface(dom_doc));

                                if (htmlDomDocument)
                                {
        
OutputDebugString(_T("Gotcha!!!...\n"));
                                }
                }
        }
}

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