We fought this battle for 5 months with a client using Payroll. the short answer is that the resolution turned out to be a new workstation for one of the users. We looked at this upside down and backwards, and had a Sage case. A new IT provider had supplied the problem workstation, but none of the other, older workstations that did not have the issue. They also provided the new workstation. Don't know what they did this time, but the issue has not recurred.