I have a web application that is supposed to handle post requests from SAP.
This has been working fine at other customers with win2k3 systems (IIS6) and win2k8 (IIS7) systems.
However, on this specific customer's site, IIS responds with a 400 response, without calling my aspx page. In fact, I don't even see it appear in the w3c log for the virtual directory.
I do see the request using Network Monitor, so I know no firewalls and the like are eating the request, and as far as I can tell, all of the fields of the request are valid (there is "content-length", it looks correct (this is a sending of a 28K tiff file - which isn't MIME encoded, curiously enough now that I think of it...)