John,
VFP periodically checks during code execution to see if Windows WM_PAINT or other events are queuing so there's a lot of technical complexity involving VFP forms painting, especially if you've a lot of code that runs every time the form is painted.
Try setting _VFP.AutoYield=.F. at least until the form is painted...
"... 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
