Guys, since there were no 1.3.1.64 server versions of PK++, I have downgraded PK++ via Steamfish to 1.2.1.64. If you remember this version is compatible with VPK servers, and is also the version distributed in the open source package.
There is no real advantage as far as I can tell to having locked netcode as in 1.3.1.64. In fact, 1.2.1.64 just denies servers for newbies, and does not encourage download of PK++, moreover it complicates things for newbies.