Yes you did answer right. In fact I realize that we'd better not mix MDIChild and non MDIChild forms in the same project.

The reason for such a work is that we want to iconize the entire app when the user chooses the iconize button onto a simple background form.

If we have a non MDIChild form displayed, and if it's modal (since we want to have only one active form at a time), the app could not be reduced.

Do you see ?