(wrong-type-argument stringp nil)

[Arnold Troeger <stssart@bkk.unocal.com>]

I'm encountering the following error when opening files or directories:
(wrong type argument stringp nil)
I can reexecute the same command and it works.  I've googled around on the net 
and haven't found anything relevent (apart from a reference to a similar error
related to comint.el)  I've also set the lisp debugger and received the following
traceback:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  internal-set-lisp-face-attribute(purple-bold :font nil #<frame emacs@exps1-w40 0x105bfa00\ >)
  set-face-attribute(purple-bold #<frame emacs@exps1-w40 0x105bfa00\ > :font nil)
  set-face-font(purple-bold nil #<frame emacs@exps1-w40 0x105bfa00\ >)
  hilit-lookup-face-create(msg-from)
  hilit-highlight-region(1 6 msg-header nil)
  hilit-rehighlight-message(nil)
  hilit-rehighlight-buffer()
  hilit-find-file-hook()
  run-hooks(find-file-hooks)
  after-find-file(nil t)
  find-file-noselect-1(#<buffer letter.txt> "~/letter.txt" nil nil "~/letter.txt" (659273 1048583))
  find-file-noselect("/home/stssart/letter.txt" nil nil nil)
  find-file("/home/stssart/letter.txt")
  dired-find-file()
  call-interactively(dired-find-file)


I appreciate any pointers to the solution.  Please let me know if there's
more information I should provide.

Thanks in advance
Arnold Troeger

-- 
Arnold Troeger				Unocal Thailand
Phone:  011-66-2-545-5456      		5th Floor, Tower 3, SCB Park Plaza
FAX:	011-66-2-545-5374		19 Ratchadapisek Road, Chatuchak
Email:  Arnold.Troeger@bkk.unocal.com 	Bangkok 10900, Thailand
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