I have owned a site since 2002 that started as PR0. It finally ended up as a PR4 about 1 1/2 years ago. I did not change much on it. Just added new products as I got them. Well about 6 months ago it dropped back to a PR1.
I have YPN on it. (Yahoo version of adsense)
I had Adbrite, but removed it in case it would cause a problem with Google
PR.
I have "Free Relevant Links" on it, but had that since the beginning.
Not sure what made it drop, but hopefully it goes back up again.
How often does Google refresh page rank?
Thanks!