SL5 out of browser main window size - preserving minimum

Question

We allow the user to resize the out-of-browser application, but we want to preserve a minimum size.

We handle the SizeChanged event like this:

        if (e.NewSize.Width < MINWIDTH)
        {
            App.Current.MainWindow.Width = MINWIDTH;
        }
        if (e.NewSize.Height < MINHEIGHT)
        {
            App.Current.MainWindow.Height = MINHEIGHT;
        }   

Unfortunately, this causes some very unatractive flickering.
Are there any other techniques for setting a minimum size?

Thanks for any ideas....