I just took a one-page crappy arbi site and updated it to actually make it look nice. Beforehand it had a PR of 3, not it has a PR of 0... WTF? Do you find that you update your sites and they get screwed in the BoondockTaint?
I had a domain that I used mainly for email, but I had stuck a one page thing there with about 50 words on it, somehow it achieved a PR of 2. I decided to use it and within a couple of days (Apr update was going on) my PR had gone to zero.