compatibility problem of whitespace-mode & PrettyControlL?

[Xah Lee <xahlee@gmail.com>]

there seems to be a compatibility problem with whitespace-mode and
both
http://user42.tuxfamily.org/formfeed-hline/index.html and
http://www.emacswiki.org/emacs/PrettyControlL

in short, when one of PrettyControlL or formfeed-hline-mode is loaded,
then the unicode in whitespace-mode disappears.

here's the steps. put the following in your .emacs:

(require 'pp-c-l)
(setq pp^L-^L-string
"                                                           ")
(pretty-control-l-mode 1)

;; Make whitespace-mode with very basic background coloring for
whitespaces
(setq whitespace-style (quote ( spaces tabs newline space-mark tab-
mark newline-mark )))
;; Make whitespace-mode and whitespace-newline-mode use “¶” for end of
line char and ▷ for tab.
(setq
 whitespace-display-mappings
 '(
   (space-mark 32 [183] [46]) ; normal space, MIDDLE DOT, FULL STOP.
   (space-mark 160 [164] [95])
   (space-mark 2208 [2212] [95])
   (space-mark 2336 [2340] [95])
   (space-mark 3616 [3620] [95])
   (space-mark 3872 [3876] [95])
   (newline-mark 10 [182 10]) ; newlne
   (tab-mark 9 [9655 9] [92 9]) ; tab
))

this should make it look like this (second screenshot):
http://xahlee.org/emacs/whitespace-mode.html

however, it seems when pretty print is loaded, all those triangle and
middle dot doesn't show.

same problem happens with formfeed-hline.

any idea what's going on?

 Xah