I don't have time to look at this in a few days, so if someone wants
to beat me to it fixing it, feel free...  (Emacs 21, latest Oort as of now.)

Debugger entered--Lisp error: (error "Unknown symbol: \x8ab")
  signal(error ("Unknown symbol: \x8ab"))
  error("Unknown symbol: %c" 2219)
  ietf-drums-parse-address("\x8abi\x8a9\x8f3\x8ac\ D\x8be\x8d4\x8aa\x8baz")
  mail-header-parse-addresses("\x8abi\x8a9\x8f3\x8ac\ D\x8be\x8d4\x8aa\x8baz")
  gnus-picon-transform-address("to")
  gnus-treat-mail-picon()
  gnus-treat-article(head)
  gnus-display-mime()
  gnus-article-prepare-display()
  gnus-article-prepare(2025 nil)
  gnus-summary-display-article(2025 nil)
  gnus-summary-select-article(nil force)
  gnus-summary-show-article(nil)
  call-interactively(gnus-summary-show-article)