Side note;

Disabling minimize button in up-right corner (or all 3 of them!) of the modal form might help reduce number of
these stuck-ups. If modal form dialog is really needed (and many times is), then I prefer large (and I mean large!) save/cancel buttons at the bottom of that form to which user naturally tabs down as he completes field entries one by one.

I have seen users minimizing modal form by mistake, and from then and on panic breaking out as nothing works any more...
They are not even aware of what they have done and it is hard to even see/realize that there is minimized form inside APP main window.
One way or another, it does not sound very well at this side of the phone... {g}