Problem with focus after closing windows form (net)

[Fermo Vignetti]

I have developed a COMM AddIn for Word 2003 with VB.NET (using project
template). This addin has a form that loads an Oracle table into a grid when
a user clicks on a command button.
The Word application is launched by a MDI application (VB.NET).
This application open a Word document and then mazimizes Word application.
If the user open the form and closes it, the MDI application is focused, not
Word.
This does not happen if the MDI application is minimized.

Thanks Fermo