When using a rounded border on an image, webkit browsers hide the border behind the image
CSS
img {
border: 10px solid #000;
border-radius: 100%;
}
HTML
<img src="http://25.media.tumblr.com/tumblr_mbjei3b3re1r30y2do1_500.jpg" />
Bug reproduced @ http://jsfiddle.net/zPpVm/
This is probably related to this Webkit bug, but I cannot find a suitable work around.