Splitters are those thin vertical (and sometimes horizontal) bars that let you resize two panes of a window at once. A good example is in the Quest Journal (see image). You've probably noticed that by default those puppies have been behaving strangely for quite some time. There are four in the Journal and several more in other places.
I've been hoping the game developers would get the internal code for splitters straightened out again, and I'm still optimistic. But until then I've written some code that should get them operational. If you download the latest Quest Journal you'll get the updated splitters. Try them out and let me know if you see any strange behavior.
With XML each splitter has to be handled separately. So the Journal is the only place where you will find them working at the moment. If there are no issues, I'll start rolling them out to other spots in the UI.
Editor's Note: All splitters are now splitting splendidly!