Hi, I'm currently using Zope 2.5.1 and have recently discovered a really nasty problem which I cannot explain and am having great difficulty finding a workaround. I have a log-in process with several forms and I use a session object to keep some data (ie. foreign keys) between forms. This has so far worked very well but now one of the values is being overwritten by 0. I can tell when this is happening but can't work out why. Brief description of what's happening: 1st form -> PythonScript: generate 'id_person' do some database work, assign session['id_person'] = id_person, assign session['username'] = username -> call 2nd form via request.response.redirect 2nd form -> PythonScript: do some more work dependent on the key 'id_person' Observations: The 'id_person' is still visible in the session object in the 2nd form but has been assigned to 0 by the PythonScript. But it is the only session variable which has been overwritten. I can't think how this would affect things but I have changed some calls from context.Objectname(request, context) to request.response('Objectname'). Any ideas? The only current workaround I can think of is to pass the key as a hidden value through the form but I'd like to avoid that if possible. Charlie