I am attempting to add the Bing Geocoding function to my existing web applications - I'm using v2.0 of the API and ArcGIS Server 9.3. I currently have a Bing Maps basemap working with the token service.
I believe the issue is this line here
geocoder = new Geocoder(Application.Current.Resources["xxxxxxxx_Xxxxxxxxxx_xxxxxxxxx"] as string);
When I select the search button, I get the message "Error: Credentials are either invalid or unspecified"
Do you have the Bing Maps Key stored as an application resource string, and are you referencing that key with a name that you have represented as the xxx's?
You're right - I had actually tried that earlier and received a webpage error instead and thought they may have been related. Novice/Self Taught Developer here - looks like it's time to troubleshoot!