[Zope] Zope behind IIS

I'm using a 404 ASP script to proxy requests from IIS to Zope. It seems to be very unreliable and I'm getting quite a lot of broken images. Is there a better way of doing this? Any help appreciated. http://www.nixonmcinnes.co.uk (proxy through IIS) http://www.nixonmcinnes.co.uk:9090 (direct into zope) Cheers Tom