When the minimum size of a window is too big to fit on the screen, MUI tries to reduce font sizes and does a new calculation. You should always design your windows to fit on a 640*200 screen with all fonts set to topaz/8.
When a window is closed (and you specified a Window.MuiID, MUI remembers its position and size and uses these values during the next opening.
After setting Window.Open to
True, you should
test if MUI was able to open the window by getting
the attribute again. If you don't and if this was
the only window of your application, the user won't
be able to do any input and your application will
seem to hang.