[XeTeX] Font strangeness

[Stephen Moye]

The following bit of plain TeX is used to fit some text into a given space. Everything works fine with every other OpenType font I have. There seems to be a problem with the new Adobe Garamond Premium Pro. For some reason that I cannot fathom the resulting text is considerably shorter than it should be. Any ideas?

%#%#%#%#%

%!TEX TS-program = xetex

\newdimen\dspsize
\newcount\divisor
\newcount\scratch

\font\dsp="Hiroshige Std Book" at .1pt
\setbox0=\hbox{\dsp The Text to Fit}%
\dspsize=\hsize 
\scratch=\dspsize \divisor=\wd0
\divide\scratch by \divisor
\dspsize=\scratch pt \divide\dspsize by 10 

\font\fitit="Hiroshige Std Book" at \dspsize

\line{\fitit The Text to Fit\hss}

\font\dsp="Garamond Premier Pro" at .1pt
\setbox0=\hbox{\dsp The Text to Fit}%
\dspsize=\hsize 
\scratch=\dspsize \divisor=\wd0
\divide\scratch by \divisor
\dspsize=\scratch pt \divide\dspsize by 10 

\font\fitit="Garamond Premier Pro" at \dspsize

\line{\fitit The Text to Fit\hss}

\font\dsp="Hoefler Text" at .1pt
\setbox0=\hbox{\dsp The Text to Fit}%
\dspsize=\hsize 
\scratch=\dspsize \divisor=\wd0
\divide\scratch by \divisor
\dspsize=\scratch pt \divide\dspsize by 10 

\font\fitit="Hoefler Text" at \dspsize

\line{\fitit The Text to Fit\hss}

\bye