Except no-where on that page does it tell me how to integrate a C# application with skype. I don't want to create a bot, accept payments, conduct interviews or add call links to my web app. I want to detect incoming calls on skype, and flash up additional data on the users screen. And to clarify, I'm talking *desktop* application, not mobile.

My advice is to have one part of your project worry about keeping the connection alive and putting that data into a database (on your side) as quickly as possible, then do any analysis against the data in your database, not on the way into the database.

Strange. You should sett up some breakpoints and find out what index the first Item in your listbox has. It should have index 0. It might be that you add the item to your listbox in a special way? I use: TheListBox.Items.Add("Some text");