Fake PR Domain's?

I was about to buy a few domains (PR2-4) a few days back when i noticed the Domain creation date.

The domain was created 2 days before and then listed for sale but i checked the PR data on prchecker.info (Pretty legit as everyone uses it) and the PR was valid.

How are people doing this and is it actually valid?

Thanks

Probably a dropped domain. Sometimes they keep the PR and sometimes they do not. If it was not dropped for very long and has a site with content it is more likely to keep the PR. The longer it sits around without a site the more chance the PR will drop.

This can happen when there is a 301 redirect and Google hasn't dropped the PR yet.

Generally it takes 2-4 weeks for PR to be updated for 301 domains, sometimes sooner.