I realize this is an old post, but in my quest to find out why my app running the Exited event before the app had even opened I found out something that I though might be useful to people experiencing this problem in the future.
When a process is started, it is assigned a PID. If the User is then prompted with the User Account Control dialog and selects ‘Yes’, the process is re-started and assigned a new PID.
I sat with this for a few hours, hopefully this can save someone time.