Francisco, how do you "abandon" the form?
The error occurs because the combo loses connection to its rowsource. This can happen if there's a "hanging reference" which is a reference to a form object that prevents the form being destroyed. If you can't find such a reference, try blanking out the combo's rowsource before releasing the form.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
