The problem is, in 0.4.0, creating an empty guarding.p2p file (or even downloading the one from the update url) in the correct spot doesn't enable the checkbox like he says it does.
The working plugin link is: http://www.apexdc.net/downloads/plugins/PeerGuardian.rar
Not fixing it in the original post, and posting that you don't want to, is sheer laziness.