>>>
>>>You could set _Screen.Visible=.f. to remove the problem completely.
>>
>>My main application menu is on there.
>
>Add it to top form.

The application does not have a top form. This form is displayed as a top-level form, with desktop = .T., in order to make it work better with several dialogs associated with it. The problem at hand is finding out why it suddenly wants to go behind the main window.