For my website I configured some custom error pages. If I generate a 404, the redirect works fine. When hitting a 400, the "bad request" text shows up instead of the configured URl.
As a test I copied the URL from 404 to 400. No change. Then I changed the redirect to a file. No change.
Any ideas?
I've run in to the same problem, and found this on msdn http://msdn.microsoft.com/en-us/library/ms690497.aspx
I'm not sure if this will work on IIS6, but it certainly works on IIS7. You need to configure httpErrors, not the custom errors
<system.webServer>
<httpErrors errorMode="Custom">
<error statusCode="400" subStatusCode="-1" path="_path" responseMode="Redirect" />
</httpErrors>
</system.webServer>