pp is part of the Par-Packer-588 package, so it looks like this one didn't install right.
Start the Perl Package Manager.
Check that
http://theoryx5.uwinnipeg.ca/ppms/package.lst has been added under Edit -> Preferences -> Repositories
There should be two entries under that tab. That one and the default entry from ActiveState.
Now, check that View -> All Packages is active, then type "PAR-Packer" without the quotes in the search box.
You should see two entries. PAR-Packer (0.976) and PAR-Packer-588 (0.973). The latter, and only the latter, should be installed in the "site" area. If not, right click that entry and install it.
(ETA: One thing that may not be readily apparent: Going right click -> Install on an entry does not actually install the package, but merely queues it for installation. You need to click the green right arrow button (center button on the right side of the search field) to actually execute all queued actions.)
Then try again.