DNS Error when exception raised

I seem to have an error on my local machine where whenever I raise an
exception it reports "Cannot find server or DNS Error". The web application
runs fine otherwise... it is hence making it hard to debug. Changing the
customerrors property in the web.config does not seem to make any difference
either.

My machine is running Windows XP Pro with the application using .Net
Framework 1.0. It has all recently been reinstalled so as far as I know there
have been no real changes to the setup.

I have tried disabling antivirus. Should I reinstall IIS?

Any help would be appreciated.

- Paul McManus