If I scroll Ensemble8 to the bottom of its list of examples and then use my scroll wheel to scroll up (it is set for 3 lines/click in WIndows 8), some of the headers on the example sections don't draw as they initially come into view. In particular, the headers for the Animation and Layout sections are most likely to not draw initially. If you can stop right on the first "mouse wheel scroll" that brings those section headers into view and they fail to draw, then any change in the scroll position seems to cause them to redraw.

Additionally, the last couple of examples in the section above the header should be visible, but aren't. They do get redrawn when you scroll again - at the same time that the section header is redrawn.