Found the problem. In testing different users with different Kixtart versions we were deleting the printer drivers out of the system directory and was expecting them to be recopied back when the script executed. However, the first time a new printer is connected using AddPrinterConnection the drivers are loaded and entries are made in the registry for the printer and its drivers. The second time it reconnects the printer the registry is checked but it does not check to see if the driver files are actually there. The simple act of opening Properties on the offending printers (and ignoring its error messages) then closing Properties with OK will reload the missing driver files.