Safari’s weird border-radius rendering issue

This is something that has been bugging me for a while. When you set -webkit-border-radius on a light object with a dark border that’s on a dark background you get some of the background-color spilling out of the edges. It looks a little bit like this:

example

Anyone have a solution? I’ve run into this 3 times recently in my work, and i’d really love to solve it.

Update: This has not been fixed in Safari 4. Crazy.