[Zope] Long running process

Hi folks, I use Zope 2.6.0. I want to compute and display large pdf reports over the web. While computing the file, the browser times out. So I followed the following howto on zope.org: http://www.zope.org/Members/don/long_procces Because I want to display the pdf file directly after processing, my redirection page checks for a session variable called pdf and returns the content of the variable as pdf file, if found, else it returns a html page refreshing after 10 seconds. While debugging, I've found out, that the variable never gets set, when the browser times out, so the redirection page is looping forever checking for the resulting pdf code. Whats wrong? Can somebody plz help me, because I'm getting mad. Regards Florian Reiser