Vanilla, the first thing I've tried to configure. I've just noticed that localhost is unreachable* so I'll take a look at the hosts file. I'm posting from the machine in question btw so mostly it just works.
You might have installed from the PPM or possibly from outside some .deb which has modified some permissions in CUPS needed files. There are certain files which need to have right user:group names that the CUPS works.
Maybe some browser .deb ? They are famous of braking Puppy CUPS.