I've been playing with git bisect in order to determine how the error was
introduced.  Here are the details of the first bad commit:

d600831eb70a0c87fca493f1e367193b88844137 is the first bad commit
commit d600831eb70a0c87fca493f1e367193b88844137
Author: Carsten Dominik <carsten.dominik@gmail.com>
Date:   Sat Oct 23 14:43:00 2010 +0200

    Use better regexp for finding image links

    * lisp/org.el (org-display-inline-images): Improve regexp

:040000 040000 024ba42a44957e10c0ca6720e5d040ebe66a92b2
7eff31113fc3dc0143cdddd857b07dd7371309a4 M lisp