Hi Bruce,
I haven't tested this with a top-level form, but I believe that modality only applies to within the particular thread, and not outside it. You can demonstrate this by simply opening up one of VFP's dialogs, such as "Open". While you can't access anything else with VFP, you can feeling move to other applications. I suspect that this explains the behavior that's been reported here.
George
Ubi caritas et amor, deus ibi est