calendar display munged

[B. T. Raven]

My calendar display looks like this:

November 2005            December 2005             January 2006
     Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr
Sa
            1  2  3  4  5                  1  2  3      1  2  3  4  5  6
7
      6  7  8  9 10 11 12      4  5  6  7  8  9 10      8  9 10 11 12 13
14
     13 14 15 16 17 18 19     11 12 13 14 15 16 17     15 16 17 18 19 20
21
     20 21 22 23 24 25 26     18 19 20 21 22 23 24     22 23 24 25 26 27
28
     27 28 29 30              25 26 27 28 29 30 31     29 30 31


What is the most likely cause of this? Is this recalculated on each
invocation of the calendar function? I thought it might have been caused
by my changing end-of-sentence repexp, tab stops, indent-tabs-mode, etc.
through custom. I know it displayed properly when I first installed emacs
(w32 21.3). After eliminating all the usual suspects I found that this in
my .emacs was causing the problem:

(custom-set-faces
  ;; custom-set-faces was added by Custom -- don't edit or cut/paste it!
  ;; Your init file should contain only one such instance.
 '(default ((t (:stipple nil :background "ghostwhite" :foreground "black"
:inverse-video nil :box nil :strike-through nil :overline nil :underline
nil :slant normal :weight normal :height 108 :width normal :family
"outline-arial unicode ms")))))

Apparently the proper display of the calendar depends on the font metrics
in force in the calendar buffer. I wan't to use arialuni.ttf in all
buffers but I also want calendar to work. Will this be possible?

Thanks,

Ed