I've been working through an issue in our test farm with our .Net application. The error being trickier by the addition of our new domain at work and our new machines. I recently got this error:
System.Net.WebException Message:
The request failed with HTTP status 407:
Proxy Authentication Required.
The problem was the .Net 2.0 application was not using the proxy exclusion list in my IE settings - for some reason. The problem was solved by the addition of this little wad of xml in the web.config:
<system.net>
<defaultProxy>
<proxy usesystemdefault="False"/>
</defaultProxy>
</system.net>
This forces .Net to not use a proxy by default, but to use a direct connection foregoing the need for authentication and making everything zippier.