All of my console sections show up with the title "Undefined" and no option to collapse them. When I use the IE9 Developer Tools to inspect the page, I can see that the section is <div class="collapseHeader" ...> and it contains <a name="console-section-8"> with a text part that says "undefined".

Looking at the same Jenkins server and the same console from FireFox shows the correct name and the option to collapse the section.