When trying to use the Version Report, I was unable to select my latest version because the drop down list is too long and doesn't allow to go down in the list.

I tried to scroll, to go down with the mouse and to use Pg Down.

Workaround

Use the following as a bookmarklet:

javascript:(function(){var dd = document.getElementById('ghx-items-trigger_drop'); 
if(dd){dd.style.top=dd.style.bottom=0;dd.style.overflowY="scroll"}})();

Create a new bookmark with the code above as the URL, and click on such bookmark whenever you're looking at the Report tab in GreenHopper with the Sprint selection list open. It will automagically scroll to the top of the dropdown, and add scrolling capabilities to it.