Testing inconsistent results between browsers for clearing the canvas by resetting the height or width to the value it's already at.
Basically it seems that what it says about resetting the canvas at http://diveintohtml5.org/canvas.html is wrong for WebKit browsers - you have to change the dimensions. A more correct doc is http://webkit.org/blog/176/css-canvas-drawing/
|Iron 5.x (Win7)||Fails|
|Safari 5.0.1 (Win7)||Fails|