Some User-scoped My.Settings string propeties are blank upon startup

Question

VB.Net, WindowsForm: I have six user-scoped strings configured in the project Settings tab. If I do a Debug.WriteLine for these immediately in the Form Load event of the project's startup form, some strings print correctly, but others print as "".

If I change the name of one of the ones that print "", then the first time I run the application, the correct value prints. After that it goes back to printing "". If I change the name again to another name that has already been used, "" still prints.

If I create a new application, any settings strings are always available upon startup. Since I have the Debug.WriteLine statement immediately at the start of my problem application, I don't see where the problem might be.