What is wrong with this:
webBrowser1.Url = new System.Uri("http://www.google.com");
MessageBox.Show(webBrowser1.Url.ToString());
When the message box tries to run it complains of a null exception.
I think I may have found the solution to my problem, it seems that I was trying to read the value before it was initalized, once I had checked this it worked perfectly. Noob error. :o(