yep Google has updated PR few weeks ago. Our all site's PR is 4. check yr outbound links sumthing huge error in yr site, check broken links. otherwise couldnt happen like this.
The main PageRank update occurred in October 2007. Any changes in PageRank after that are due to penalties or the lifting of penalties.
I was a PR 4 on a few sites and now im down to 2 or three. Some poeple say it has to do with ADS. I think it has to do with a major change in their algo. We need to learn what they did but meanwhile just do your things and youll climb back up.
I also suffering from Google's Page Rank update..I used to have PR 4,3,3 for my blogs in OCtober. 2 weeks after, all PR's became 2 and now they turned into a 0.I really don't know why but I want my PR's back coz it's affecting my opps a lot.
one of my friends sites got hit from a PR3 to a PR0 recently too. More google craziness, the sooner the get rid of PR the better.