I have a site that has approx. 30 plr articles. So noine of the content is unique. After the current PR update, the site increased from PR0-PR1. The site has a couple of related PR4 links and some PR2 links. So, why didn't the site get a higher PR?

My theory is that the plr articles are in the supplemental index and the supplemental pages aren't flowing any PR back to the homepage.