Filters not working

[tsd@tsdye.com (Thomas S. Dye)]

Aloha all,

After an upgrade from 8.0.3 this morning I'm unable to export a large
writing project that has kept me from reading the ML regularly for the
last few months. It seems that filters that used to work, no longer do
so. For example,

  #+name: tsd-parencites
  #+BEGIN_SRC emacs-lisp 
  (defun tsd-latex-filter-parencites (text backend info)
    "Replace parencites placeholders in Beamer/LaTeX export."
    (when (memq backend '(beamer latex))
      (replace-regexp-in-string "π" "\\parencites" text nil t)))
  (add-to-list 'org-export-filter-plain-text-functions
               'tsd-latex-filter-parencites)
  #+END_SRC

now lets pi slip through into the LaTeX output, giving this error:

ERROR: Package inputenc Error: Unicode char \u8:π not set up for use with LaTeX.

My question, is whether this filter is obviously broken given recent
changes to Org-mode?  Any pointers greatly appreciated.

If not, I'll get on with it and try to track down the problem.

All the best,
Tom

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