Judith,
information about the system toolbars is stored in the foxuser.dbf. If the toolbar is visible while you create your application and you are deploying the foxuser with your app, the toolbar will be visible when the app is run.
Try to create your app with hidden toolbar or have an extra foxuser.dbf for deployment.
Hope that helps
I've acquired quite a taste for a well-made mistake... [Fiona Apple]