Hi, Martin,
This is just a 'guess', but maybe you need a form refresh. I've had things like that happen.
However, here's something to think about...I often reserve the bottom row of most forms for a 'status' label...it has a black background with a white foreground for the text, so it usually stands out. In the label, I display things like 'retrieve data...please wait'...to me, that's a little cleaner than popping up another form, though that's a subjective view. Anyway, something to think about.
Kevin