I don't know if you can see this thread without being a member of bladeforums, but here's the
blade forums link.
The analysis is also posted
here on Google Docs, which requires you to have a Google account.
In reading the Google version, I'll admit that I was wrong, in that the geometry does matter somewhat. A simple semi-circular cutout reduces the stress the most, and sharp angles bring the stress levels back up, where the sharp angles occur.
Hope this helps,
F