Evergreen 1.6.1.9a was released shortly after 1.6.1.9 to address security issues.
Change link on Code Museum Page accordingly.
Credit to: Nat Schilling and Chris Sharp
<h4>1.6.1 series</h4>
<ul class="bullet">
-<li class="content">(2011-10-04): (<a href="/downloads/Evergreen-ILS-1.6.1.9.tar.gz">server, 1.6.1.9</a>) (<a href="/downloads/Evergreen-ILS-1.6.1.9.tar.gz.md5">md5</a>)</li>
+<li class="content">(2011-10-06): (<a href="/downloads/Evergreen-ILS-1.6.1.9a.tar.gz">server, 1.6.1.9a</a>) (<a href="/downloads/Evergreen-ILS-1.6.1.9a.tar.gz.md5">md5</a>)</li>
<li class="content">(2011-03-16): (<a href="/downloads/Evergreen-ILS-1.6.1.8.tar.gz">server, 1.6.1.8</a>) (<a href="/downloads/Evergreen-ILS-1.6.1.8.tar.gz.md5">md5</a>)</li>
<li class="content">(2011-02-04): (<a href="/downloads/Evergreen-ILS-1.6.1.7.tar.gz">server, 1.6.1.7</a>) (<a href="/downloads/Evergreen-ILS-1.6.1.7.tar.gz.md5">md5</a>)</li>
<li class="content">(2011-01-04): (<a href="/downloads/Evergreen-ILS-1.6.1.6.tar.gz">server, 1.6.1.6</a>) (<a href="/downloads/Evergreen-ILS-1.6.1.6.tar.gz.md5">md5</a>)</li>