For anyone else who might search the list in the future:
Microsoft has confirmed that ASP error handlers in current versions of IIS 6 do not, can not, and will not -- no matter what the security settings -- get at POST data. There's a discussion of the changes at:
I think that is not 100% true-- I am not sure where the difference lies -- but as we discussed I am using ASP404 on Windows 2003 (at http://www.coursesbywire.com) with form Posting functioning. The only issue (that I ran up against and had to solve) is that the method used in ASP404 to determine whether the original request was a POST or a GET no longer works on Win2003 (as it did on Win2000) -- it is necessary to introduce a kludge in the ASP code.
http://blogs.msdn.com/david.wang/archive/2005/11/29/Child_URL_Execution_and_...
The author confirmed that the changes also affect custom error handlers.
So, the days of serving Zope pages on IIS via the 404handler.asp approach are pretty much over.
Not quite -- but maybe numbered. I agree though that starting out now using it when it was not previously in use might be a bad plan. I am not totally sure what is causing your problem but on my (fully patched Win2003)server the Post data is available. I had a look at Enfold's Proxy when I this issue first came up for me but found that it did not solve my problem (though it could be that I just didn't understand something about it). In my case putting Apache in front did not seem a reasonable solution either as I am running IIS on the box and needed it to stay.