[Xy-pic] arc overshooting endpoint

[Leslie Saper]

Hello,

I am using xy-pic with the pdf option and the color extension.  The 
documentation indicates that xypdf now supports color.  However when I 
define a color with \newxycolor and process the minimal code below 
through pdflatex I get a warning that the current driver does not 
support color, even though the log earlier shows the pdf driver 'color' 
extension support being loaded.  The problem does not occur if I use 
plain tex instead of of latex.  It also does not occur if I use the 
(non-Xy-pic) color or xcolor packages to define the colors.

What am I doing wrong?  Is it possible to use \newxycolor simply with 
the pdf option and latex?

\documentclass{article}
\usepackage{xy}
\xyoption{pdf}
\xyoption{color}
\newxycolor{lightgrey}{.33 gray}
\begin{document}
\xy
*[lightgrey]\hbox{Grey}
\endxy
\end{document}

I am using LaTeX2e <2009/09/24> with Wy-pic version 3.8.5 and PDF driver 
v.1.6.  A copy of the log file is available at

http://www.math.duke.edu/~saper/test-pdf.log

Thank you.

-- 
Leslie Saper                    e-mail: saper at math.duke.edu
Department of Mathematics       phone: 919-660-2843
Duke University                 fax: 919-660-2821
Box 90320
Durham, NC   27708-0320
USA