Question; You said that the printer did not work under 21354 but did under 21343. Did you compare the driver for the printer in Device Manager on each build?
@lacrumb,
Yes, they changed the usbprint.sys driver and also the spoolsv.exe, by doing that they screwed up, some USB printers are no longer working with 21354 while they work fine with 21343 or any previous build.