It appears the release notes link in the README file of the source is missing.
3.8.1p1 was a Portable-only release and the release notes are: http://www.openssh.com/txt/release-3.8.1p1 Maybe we should put a copy (or a pointer) at "release-3.8.1"?
I've put a small note and a pointer to http://www.openssh.com/txt/release-3.8.1p1 at release-3.8.1. It will show up on the main site in an hour or two.