Laurent, can you attch your /etc/cups/cupsd.conf?
Your usb_printer.txt file shows that the permissions of your printer's USB device files do not get set. For me it looks like a problem of UDEV.
Laurent, can you attch your /etc/cups/ cupsd.conf?
Your usb_printer.txt file shows that the permissions of your printer's USB device files do not get set. For me it looks like a problem of UDEV.