If you are wondering how your site able to get PR even with 0 content on it. Only this page has important backlinks:
http://www.naijaict.com/2012/04/africa-family-planning-force-for-good.html
So when you parked this domain to your host,
it made all your indexed pages as live page, showing some ads for all page visits instead of redirecting it to homepage. So when google visited your above page, it found live as ads were visible on it although no content on it, so it retained its PR3.
My advice to make your above mentioned page live as soon as possible to get linkjuice.
Thanks