I thought I'd change the font to something none standard from the list of font available on my computer. When I tried to compile the following document, the text that should appear along the spokes was scattered all about the page.
\documentclass{article}
\usepackage{fontspec}
\setmainfont{ScottMorrison}
\usepackage{lipsum}
\usepackage{graphicx}
\usepackage{tikz}
\def\aemonth{\ifcase\x\or
{Jan}\or
{Feb}\or
{Mar}\or
{Apr}\or
{May}\or
{Jun}\or
{Jul}\or
{Aug}\or
{Sep}\or
{Oct}\or
{Nov}\or
{Dec}\else
{ERR}\fi}
\begin{document}
\begin{tikzpicture}
\node[circle,
draw,blue,
minimum size=1em,
inner sep=0pt] (C) at (-1,0) {};
\def\prevx{1}
\foreach \x in {1,2,...,12}
{
\pgfmathparse{-(\x-1)*30+90}
\def\myRotAngle{\pgfmathresult}
\node[anchor=180+\myRotAngle] at (C) {\rotatebox{\myRotAngle}{\hspace*{1.5em}(\x)text along spokes}};
\node[circle,draw,red,minimum size=4pt,anchor=180+\myRotAngle] (C label \x) at ([shift={(\myRotAngle:4)}]C) {\textcolor{black}{\aemonth}};
\draw (C) -- (C label \x);
\draw (C label \x) -- (C label \prevx);
\xdef\prevx{\x}
\ifnum\x=12\relax
\draw (C label 1) -- (C label \prevx);
\fi
}
\end{tikzpicture}
\end{document}
Resulting in:

Everything works fine if I eliminate the font declaration and compile with pdflatex.

I don't do much, if anything at all, with xelatex. What do I need to do to get xelatex to play nicely with tikz?
The font can be found in Using a handwriting font from myscriptfont.com
UPDATE
I get the same problem if I just use xelatex without worrying about the setting the font with \setmainfont or whether or not I load \usepackage{fontspec}. Per the comments, here's the relevant section of my log file after using \listfiles:
*File List*
article.cls 2007/10/19 v1.4h Standard LaTeX document class
size10.clo 2007/10/19 v1.4h Standard LaTeX file (size option)
fontspec.sty 2013/05/20 v2.3c Font selection for XeLaTeX and LuaLaTeX
expl3.sty 2013/07/12 v4544 L3 Experimental code bundle wrapper
l3names.sty 2012/12/07 v4346 L3 Namespace for primitives
l3bootstrap.sty 2013/01/08 v4420 L3 Experimental bootstrap code
etex.sty 1998/03/26 v2.0 eTeX basic definition package (PEB)
l3basics.sty 2013/07/09 v4521 L3 Basic definitions
l3expan.sty 2013/07/09 v4521 L3 Argument expansion
l3tl.sty 2013/04/24 v4482 L3 Token lists
l3seq.sty 2013/05/26 v4500 L3 Sequences and stacks
l3int.sty 2013/04/24 v4482 L3 Integers
l3quark.sty 2013/07/09 v4521 L3 Quarks
l3prg.sty 2013/04/24 v4482 L3 Control structures
l3clist.sty 2013/05/26 v4500 L3 Comma separated lists
l3token.sty 2013/04/24 v4482 L3 Experimental token manipulation
l3prop.sty 2013/01/09 v4423 L3 Property lists
l3msg.sty 2013/01/08 v4412 L3 Messages
l3file.sty 2013/05/01 v4483 L3 File and I/O operations
l3skip.sty 2013/01/13 v4444 L3 Dimensions and skips
l3keys.sty 2013/07/12 v4544 L3 Experimental key-value interfaces
l3fp.sty 2013/07/09 v4521 L3 Floating points
l3box.sty 2013/04/24 v4482 L3 Experimental boxes
l3coffins.sty 2012/09/09 v4212 L3 Coffin code layer
l3color.sty 2012/08/29 v4156 L3 Experimental color support
l3luatex.sty 2012/08/03 v4049 L3 Experimental LuaTeX-specific functions
l3candidates.sty 2013/07/09 v4521 L3 Experimental additions to l3kernel
ifpdf.sty 2011/01/30 v2.3 Provides the ifpdf switch (HO)
xparse.sty 2013/07/12 v4544 L3 Experimental document command parser
fontspec-patches.sty 2013/05/20 v2.3c Font selection for XeLaTeX and LuaLaTe
X
fixltx2e.sty 2006/09/13 v1.1m fixes to LaTeX
fontspec-xetex.sty 2013/05/20 v2.3c Font selection for XeLaTeX and LuaLaTeX
fontenc.sty
eu1enc.def 2010/05/27 v0.1h Experimental Unicode font encodings
eu1lmr.fd 2009/10/30 v1.6 Font defs for Latin Modern
xunicode.sty 2011/09/09 v0.981 provides access to latin accents and many oth
er characters in Unicode lower plane
eu1lmss.fd 2009/10/30 v1.6 Font defs for Latin Modern
graphicx.sty 1999/02/16 v1.0f Enhanced LaTeX Graphics (DPC,SPQR)
keyval.sty 1999/03/16 v1.13 key=value parser (DPC)
graphics.sty 2009/02/05 v1.0o Standard LaTeX Graphics (DPC,SPQR)
trig.sty 1999/03/16 v1.09 sin cos tan (DPC)
graphics.cfg 2010/04/23 v1.9 graphics configuration of TeX Live
xetex.def 2013/04/29 v0.96 LaTeX color/graphics driver for XeTeX (RRM/JK)
fontspec.cfg
lipsum.sty 2011/04/14 v1.2 150 paragraphs of Lorem Ipsum dummy text
tikz.sty 2013/08/05 v2.10-cvs (rcs-revision 1.129)
pgf.sty 2013/08/23 v2.10-cvs (rcs-revision 1.13)
pgfrcs.sty 2010/11/07 v2.10-cvs (rcs-revision 1.25)
everyshi.sty 2001/05/15 v3.00 EveryShipout Package (MS)
pgfrcs.code.tex
pgfcore.sty 2010/04/11 v2.10-cvs (rcs-revision 1.7)
pgfsys.sty 2013/08/23 v2.10-cvs (rcs-revision 1.46)
pgfsys.code.tex
pgfsyssoftpath.code.tex 2008/07/18 (rcs-revision 1.7)
pgfsysprotocol.code.tex 2006/10/16 (rcs-revision 1.4)
xcolor.sty 2007/01/21 v2.11 LaTeX color extensions (UK)
color.cfg 2007/01/18 v1.5 color configuration of teTeX/TeXLive
pgfcore.code.tex
pgfcomp-version-0-65.sty 2007/07/03 v2.10-cvs (rcs-revision 1.7)
pgfcomp-version-1-18.sty 2007/07/23 v2.10-cvs (rcs-revision 1.1)
pgffor.sty 2013/07/18 v2.10-cvs (rcs-revision 1.24)
pgfkeys.sty
pgfkeys.code.tex
pgfmath.sty
pgfmath.code.tex
pgffor.code.tex
tikz.code.tex
t3cmr.fd 2001/12/31 TIPA font definitions
***********
\listfilesoutput to the question? – Joseph Wright Sep 07 '13 at 19:51\setmainfontline. I'm using TL2013 and I tried with both PGF from TL2013 and PGF from CVS. – Andrew Stacey Sep 07 '13 at 19:54cvsversion directly fromsourceforgeto compile correctly even though I'm following steps as outlined at Paul Gaborit's answer. I've updated the\listfilesresult. – A.Ellett Sep 07 '13 at 20:15\listfiles. Can you doless $(kpsewhich pgfsys-dvipdfmx.def)(or take a look at it somehow) and post the version of that (first non-comment/blank line). Mine saysv 1.12 2013/08/28. – Andrew Stacey Sep 07 '13 at 20:34Settings (admin)menu. – percusse Sep 07 '13 at 20:56v 1.11 2013/08/01– A.Ellett Sep 07 '13 at 21:11\listfileandkpsewhichtogether to create an answer that might help someone else debug what amounts to an current version issue. – A.Ellett Sep 07 '13 at 22:40