ADP - totals on subform

I'm using Access 2003 adp.
My db users like to browse transactions through a form, and then filter them
"by selection" (by customer or product). A field SumSales on form's footer
should update based on their filters, but it doesn't.
I have no problem accomplishing this in mdb, but adp doesn't do it the same
way.

SumSales text field on the form footer doesn't change value when I filter by
selection - it stays the same as when the form was loaded. Record source is a
stored procedure, but I've tried using a table - no difference.
How can I resolve this problem?

Thanks,
Lana