Thanks, but I don't believe that would be worth trying. I have 40+ years of experience in IT and I suspect the problem is in QuickBooks code. No other programs exhibit this behavior. The problem is not with the monitor or screen, I suspect it is in the code that tracks the mouse pointer position and enables QB features based on that location. The screen on which this feature of QB does not work is configured in Windows to be above the primary monitor(s). Thus, the mouse pointer screen position would use negative numbers for the Y dimension. I suspect that the QB code that deals with negative screen coordinates is failing. In fact, if I tell Windows that the top screen is to the left of the primary monitor, not above it--thus with all 3 monitors on one level (therefore the Y dimension would never go negative)--QuickZoom works fine. However, I am hoping I will be able to use the actual layout of the screens in Windows and QuickBooks. I'd appreciate it if you would escalate this to explore that line of attack. Thanks.