[Zope] pdf on-the-fly (again)

Hi, I'm using html2pdf external ( http://zope.org/Members/mjablonski/howtoPDF) script to generate on-the-fly pdf. I usually add the URL /html2pdf to the document I want to be converted into pdf. The problem comes when I pass a parameter to the URL I want to convert (i.e. detail?param=myvalue), the corrisponding pdf URL is detail?param=myvalue/html2pdf , but it does not work since "param=myvalue/html2pdf" is evaluated as QUERY_STRING and then the html2pdf script is never called. how can I force the html2pdf script to work? thks in advance Alex