Our site also shows PR0 on re-written URL's, but it ranks well. That's all we care about, and I'm guessing all that you'll care about. We changed our URL's a couple weeks before the last public
PR update and it just hadn't been crawled soon enough before that update to show
PR on most of our pages.
I anticipate that most of our pages will be assigned
PR at the next update, but I don't really care since we're seeing good SERPs for our pages.
Brian.