Payroll Items - Making them inactive

I have a payroll client that has a large number of old pay items that are no longer active but I cannot make them inactive or remove them from the employees standard pay list as I receive a message that it is linked to a time sheet.  Some of these items have not been used for 2 or 3 years and they clog up the pay run when I am preparing the fortnightly pays.  Is there any way to make them inactive so they are no longer visible, or, to remove them from the employees standard pay?  Seems crazy that such old items cannot be removed or at least made non-visible.