Clicking Renumber in Employee Maintenance shows "You cannot delete and employee..."

I know there is a bug fix for renumbering employees, but I have that installed.  On two different test systems, on Payroll 2.20 with fixes installed, if I click on the Renumber button in Employee Maintenance, I get "You cannot delete an employee record if the employee has existing payroll history, deduction history, earnings history, tax history".  The only reason I was trying to renumber is because a client reported losing the Rate Audit information for an employee when renumbering and I wanted to test it.  So why can a customer renumber and not I?