In the manual, sprite blends are linked to this page:
https://developer.mozilla.org/samples/canvas-tutorial/6_1_canvas_composite.html
But I'm not sure if I'm either doing it wrong, or it's bugged?
Here is what it shows the effect does on the site ('destination out' in B):
<img src="https://dl.dropbox.com/u/1024727/c2/blend.PNG" border="0">
What it looks like when I try using 'destination out':
<img src="https://dl.dropbox.com/u/1024727/c2/destination.PNG" border="0">
My capx file