Well put.I don't like to get into debates with people, but I'm having a hard time believing that 30 of your websites got a PR 9 backlink (an actual PR 9), and it showed up on your Yahoo Backlinks.
A PR 9 is an equivalent of having Yahoo itself backlink to you, and if that was the case, then you would be outranking almost all of your competitors.
The backlink that you get is a PR 0, however, it has authority since it's from a PR 9 website, but it's not a PR 9 backlink. There's a difference.
It is not a PR 9 backlink it has NO PR, check it out it will show NA