AttributedString draws out of bounds?

Using the latest tip, Win8.1 with DirectWrite enabled.

I have the following code:

AttributedString as;

as.setWordWrap(AttributedString::none);
as.append(text, itemFont, colour);
as.setJustification(Justification::centredLeft);
as.draw(g, itemPosition.toFloat());

The String text is some 200 characters long and the Rectangle, itemPosition is 50 pixels wide and it's height is the same as the font height.

I'd expect just about 1 line of 50 pixels of text, ending with '...'

Instead, the drawing completely ignoreד the given width and text is drawn way beyond the 50 pixels range.

What am I missing here?