What do you mean when you say the user clicks on the page to zoom in and out? Do you have something special set up to deal with zooming?
I did a quick test of a report calling a UDF to add to a total. I zoomed in and out from the toolbar. I zoomed in and out from the right-click menu. I navigated back and forth through a bunch of pages. No matter what I tried, the total was always right.
Cathy Pountney, Microsoft Visual FoxPro MVP Memorial Business Systems, Inc. (www.mbs-intl.com)