I am still getting 403 Forbidden when I try to modify a printer.
(I had added two Samba printers on an earlier install, they are still listed in the N900, but not working from the N900 now.)

Also, printer administration via localhost:631 does not ask me for a password, & I seem to recall that it did in an earlier cups install that I had working well enough to add network printers at work.

I will work with it some more.