>>Can you see if it's form-class related? That is, create a very simple top-level form, and in the code just use:
>>DO FORM mySDI
>>and see if it still occurs.
>
>I created a new SDI form derived from the basic VFP form class (instead of my own form class) and launched the SCX like you mentionened. As expected, the form is on top of the VFP main screen. Then I saved that form as a class, instantiated it in my application object and showed the instance. It appears behind the _SCREEN!
>
>Yesterday I read your reply to another SDI related thread. That let me doubt whether I am using the right approach to implement a SDI user interface. Would it be better to hide the VFP main screen and to create a top level form which serves as application main screen?

Absolutely, IMO. Mixing TLs and the main _screen is looking for trouble. I've done all apps without _screen for the past few years, and it's terrific. One has much more control with a TL and it's PEMs than with the main _screen. Also, note that if you're using a TL as an application main screen, you can also use it as your application object instead of the old way of using a separate application object - something else I really like.