Is there a conflict between the package tabularx and epstopdf?

Question

I am trying to use epstopdf to convert .eps files to .pdf on-the-fly, yet I can't get it to work with the tabularx package.

In summary: Can anyone tell my why the following example works?

\documentclass[pdftex,10pt,a4paper]{article}
\usepackage[pdftex]{graphicx}
\def\pdfshellescape{1}
\usepackage{epstopdf}
\usepackage{amssymb,amsmath, amsfonts}
\usepackage{longtable}
\usepackage{ltablex}
\usepackage{tabularx}


\def\pth{X:/Results/results/pictures}
\def\ig{\includegraphics[scale=0.8,keepaspectratio]}


\begin{document}

\begin{longtable}{|c|}
\ig{\pth/result5}\\
\end{longtable}

\end{document}

And when I replace:

\begin{longtable}{|c|}
\ig{\pth/result5}\\
\end{longtable}

with:

\begin{tabularx}{\linewidth}{X}
\ig{\pth/result5}\\
\end{tabularx}

It no longer compiles?

I receive the following error:

! Package pdftex.def Error: File `X:/Research/Results/lung_project_results/pict ures/result5-eps-converted-to.pdf' not found.

@Kurt: I'm using Miktex 2.9.4476

When I add \listfiles, the log file outputs the following:

---

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)
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 2007/01/18 v1.5 graphics configuration of teTeX/TeXLive
pdftex.def 2011/05/27 v0.06d Graphics/color for pdfTeX
infwarerr.sty 2010/04/08 v1.3 Providing info/warning/error messages (HO)
ltxcmds.sty 2011/11/09 v1.22 LaTeX kernel commands for general use (HO)
epstopdf.sty 2010/02/09 v2.5 Conversion with epstopdf on the fly (HO)
epstopdf-base.sty 2010/02/09 v2.5 Base part for package epstopdf
grfext.sty 2010/08/19 v1.1 Manage graphics extensions (HO)
kvdefinekeys.sty 2011/04/07 v1.3 Define keys (HO)
kvoptions.sty 2011/06/30 v3.11 Key value format for package options (HO)
kvsetkeys.sty 2012/04/25 v1.16 Key value parser (HO)
etexcmds.sty 2011/02/16 v1.5 Avoid name clashes with e-TeX commands (HO)
ifluatex.sty 2010/03/01 v1.3 Provides the ifluatex switch (HO)
pdftexcmds.sty 2011/11/29 v0.20 Utility functions of pdfTeX for LuaTeX (HO)
ifpdf.sty 2011/01/30 v2.3 Provides the ifpdf switch (HO)
amssymb.sty 2009/06/22 v3.00
amsfonts.sty 2009/06/22 v3.00 Basic AMSFonts support
amsmath.sty 2000/07/18 v2.13 AMS math features
amstext.sty 2000/06/29 v2.01
amsgen.sty 1999/11/30 v2.0
amsbsy.sty 1999/11/29 v1.2d
amsopn.sty 1999/12/14 v2.01 operator names
ltablex.sty 1995/11/06 v1.0 Modified tabularx
longtable.sty 2004/02/01 v4.11 Multi-page Table package (DPC)
tabularx.sty 1999/01/07 v2.07 `tabularx' package (DPC)
array.sty 2008/09/09 v2.4c Tabular extension package (FMi)