Speaking the truth here. And you can also see when the domain was dropped and kept the PR for a little longer by checking the cache and the indexed pages. If the pages don't load, then you're dealing with a dropped domain with a bit of fresh content. What this means is that the PR is valid, but it's gonna drop really fast. More than any PR checker- use your head!
for this time ive been using diagnostico to detect this fake PR. maybe this can be ur additional resources.