The remote server returned an error: (500) Internal Server Error.

[Steve]

I recently implemented a webservice that was called by a c#
application.
It all ran fine when they were both on the same server,
however when we moved the webservice to another machine (and changed
the url of the HttpWebRequest) ,
it only returned (500) errors unless we also moved the client
application over to the same machine, whereupon it resumed working.
After messing with the IIS settings and various things in the the C#
application, I eventually found that adding:

<webServices>
<protocols>
<add name="HttpPost" />
</protocols>
</webServices>

inside the <system.web> of the Webservice's Web.config fixed the
problem.

My question is why was this not preventing the Webservice from properly
working when the client resided on the same machine?

If nothing else, I hope this helps anyone else with any similar
problems as I spent way too long trying to hunt this down :)