Trouble with ESS and Sweave

Last time I tried to sweave a document from with Emacs+ESS, I was using an earlier version of ESS (the current version is 5.8), and things seemed to be fine. Today when I tried to sweave a simple document and produced PDF output, I got error message of ".pdf": exited abnormally with code 2". I posted a message to the ESS mailing list, but so far no solutions have been reported. 


Here is a very simple .Rnw file I used to reproduce the error: 

---------------------------------------
\documentclass[12pt]{article}

%\usepackage{tikz}
%\usepackage{fullpage}
\usepackage{Sweave}

\begin{document}

This document outlines the analysis to be carried out to look at the
relationship between prenatal famine exposure and fetal loss risk.

\end{document}
-----------------------------------------

Before this can be fixed, I will rely on Eclipse for all my sweaving. 

---------------- April 26 ------------------------

Here is my own solution: 

from line 177 of ess-svy.el:

-      (shell-command (concat

-       (if (and ess-microsoft-p (w32-shell-dos-semantics))

-           "start \"" pdfviewer "\" \"" namestem ".pdf\""

-                 "\"" pdfviewer "\" \"" namestem ".pdf\" &"))))

+      (shell-command (concat

+                 "\"" pdfviewer "\" \"" namestem ".pdf\"")))