How to make fiddler trace web traffic when running as a different user

I added the following to application.config (console application) and still doesn't collect traffic when it is run under a different user account on the same machine.

<system.net>
 <defaultProxy>
  <proxy autoDetect="false" bypassonlocal="false" proxyaddress="http://127.0.0.1:8888" usesystemdefault="false" />
 </defaultProxy>
</system.net>