I've been having sporadic key signing issues so I upgraded from CVS
this morning and tried the latest. It's still happening:

Debugger entered--Lisp error: (error "Sign error")
  signal(error ("Sign error"))
  error("Sign error")
  mml2015-pgg-sign((part (sign . "pgpmime") (tag-location . 477) (contents . "...")))
  mml2015-sign((part (sign . "pgpmime") (tag-location . 477) (contents . "...")))
  mml-pgpmime-sign-buffer((part (sign . "pgpmime") (tag-location . 477) (contents . "...")))
  mml-generate-mime-1((part (sign . "pgpmime") (tag-location . 477) (contents . "...")))
  mml-generate-mime()
  message-encode-message-body()
  gnus-inews-do-gcc()
  gnus-agent-possibly-do-gcc()
  run-hooks(message-sent-hook)
  message-send(nil)
  message-send-and-exit(nil)
* call-interactively(message-send-and-exit)

User error, I presume. Clues solicited.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com> | Everything should be made as simple as
http://nwalsh.com/            | possible, but no simpler.