I don't understand something. My Goolge PR values used to be a 6. Then, last few weeks it was a 5. Now, over the last few days, it changes every few hours between 3, 4, and 5. It was a 5 an hour ago, and now it is a 3! Does anyone know what is going on? I read on Google help that they only recalc this number once a month.
And, during this time, the number of other sites that have links to me has been increasing.
It hasn't been 'once a month' for a long time now, but the last PR change I've seen on the toolbar is April 23rd. (as little as 11 days between PR updates, and as long as 50 days over the past 2 or 3 quarters.
I have never seen anything like you are referring to - and I monitor a ton of sites.