[pdftex] strange bug!

[Paulo Ney de Souza]

In the process of porting a package to pdflatex we found the following 
strange behaviour in "pdflatex" and hopefully someone here can account
for what is going on.

The file below, when processed with pdflatex and the 3 comments does NOT
produce the second (uncommented) picture. If the 3 comments  are taken 
OUT then it produces both pictures! The (strange) behaviour does not show
when one use stardard "latex"... so I am assuming it is a problem with 
"pdflatex". Does anyone knows what is going on ?

----------------------------------------------------------------------
\documentclass{report}
\usepackage[pdftex]{graphicx}
\begin{document}
This is a figure:

%\begin{figure}[h]
%\includegraphics{foo}
%\end{figure}

\begin{figure}[h]
\includegraphics[bb= 100 300 200 500]{foo}
\end{figure}

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

The problem seems to be independent of the graphics files foo.{ps,pdf}
but just in case anyone needs it, you can get it at

	http://www.math.berkeley.edu/~desouza/badpdf/

Paulo Ney