cc-mode in emacs 23.2 goes into infinte loop

[jdiamond]

I have the following file (which is actually my real mode file with
almost everything removed):

----------------- zsd-c-mode.el -------------------
(require 'cc-mode)

(eval-and-compile
   (c-add-language 'zsd-c-mode 'c-mode))

(defvar zsd-c-mode-syntax-table nil
    "Syntax table in use in zsd-c-mode buffers."
)

(defun
    zsd-c-mode ()
    "Major mode for editing C source code.
    Based loosely upon the Unipress Emacs electric-c mode."
    (interactive)
    (c-init-language-vars zsd-c-mode)
    (c-common-init 'zsd-c-mode)
    (setq zsd-c-font-lock-keywords-3 nil)
)
---------------------------------------------------

If I start up emacs 23.2 with
        emacs -Q qqq.q
and them
        M-x load-file RET ~/emacs/zsd-c-mode.el
and then
        M-x zsd-c-mode RET
and then in the buffer I type
        #define as(
when I hit the '(' emacs goes into an (apparently) infinite loop.
(The '(' does not actually appear in the buffer until I hit ^G.)

Tracking it down (a bit), I see that in cc-mode c-neutralize-CPP-line
is not doing The Right Thing any more.  Specifically,
        (c-put-char-property (nth 1 s) 'syntax-table '(1))
is not changing anything in the result of the following call to
        (parse-partial-sexp beg end -1)
and so c-neutralize-CPP-line loops.

Before I file this as a bug, are there any cc-mode experts here who
can comment on whether I am committing some grievous sin with the code
above?  (This worked in earlier versions of emacs, but perhaps the
above has suffered from bit rot by changes to emacs.)

Thanks.
                                Jim