Form Printing/Unbound Objects Blank

BACKGROUND: Have a form with two subforms imbedded in a tab control. Each
subform has, in its Form Footer, a totals row. each text control in the
totals row contains =Sum(whatever) as its control source, and that works fine
EXCEPT...

In one instance only, my detail data involves a ratio, and using
=Sum(ratios) or =Avg(ratios) in the totals row would produce a mathematically
incorrect result. I am able to get the correct result in that control for
the screen display by doing a calculation in connection with the Form Load
event of that form, but when I try to print the form, that control shows a
blank. Need some help figuring out how to to get than number to show up in
the print output. (Actually, I already have a workaround that involves just
using the value as a caption in a label formatted to look like a text box,
but I'd really like to know why that one text box won't print and what I can
do about it.)