You use dispatcher in IIS 6/7. For every http POST request to IIS, IIS returns 404 error. You check your dispatcher configuration (dispatcher.any) and see that POST requests are not blocked by dispatcher.
ISAPI is not allowed
You need to allow ISAPI in order for the dispatcher to work with all other http methods. See the attached screenshot.
Addition configuration information (IIS 7/7.5):
- Make sure that you have added the Virtual 'scripts' Directory to you website containing physical path to '<Dir>/Inetpub/scripts'
- If you are converting the 'scripts'(virtual directory) to an application using 'convert to application' options then make sure that the 'Application pool' used for the 'scripts' and for the Website should be the same.
If the issue still occurs, please enable IIS tracing