After the comment by SuperCruncher, I re-ran the example code from PPM::Repositories which I called Repo.pl.
I noted that I got a nice list of repositories.
But when I did a ppm rep, I got:
Repositories: [1] ActiveState PPM2 Repository [2] ActiveState Package Repository [ ] bribes [ ] crazy58 [ ] datetime [ ] esoft [ ] gtk [ ] jenda [ ] openi [ ] roth [ ] sablot [ ] savage [ ] soulcage58 [ ] theory58 [ ] theory58SHumph! Ok, they're listed but not active.