xml/xsl document events for debugger (pagehide, pageshow)

I have been trying to add support for XSLT pages to Firebug. The basic 
problem is that XSLT does not seem to signal these events:
     win.addEventListener("pagehide", onUnloadTopWindow, true);
     win.addEventListener("pageshow", onLoadWindowContent, true);
     win.addEventListener("DOMContentLoaded", onLoadWindowContent, true);
Does anyone know if this is a known problem, a reflection of the 
incomplete state of XSLT implementation, or working as designed?

Thanks,
John.