From what C=E9sar told me about a patch for the USB driver, I suspect
that the problem is that the CUPS 1.2 USB driver expects to read from
the printer.  Despite our driver printing

  ulpt0: using bi-directional mode

I believe that it does not really read data from the printer.

So, all the reports are consistent.  Does this statement fit all
evidence?

  cups 1.1 generally works
  cups 1.2 work on NetBSD with ipp, BSD lpd, parallel
  cups 1.2 does not work on NetBSD with ulpt (usb printers)

  cups 1.2 from our pkgsrc probably works fine on Linux even with usb print=
ers

Any contrary reports?

--=20
    Greg Troxel <gdt@ir.bbn.com>