From Preferences menu, add this url:
http://ppm.tcool.org/archives/
and I strongly recommend to disable (click yellow icons of) other repositories, especially ActiveState's. Also, avoid ActivePerl 5.8.8.818 and 819. PPM bundled with these builds are somewhat broken and backward-incompatible.
Type at a DOS prompt:
ppm rep add tcool http://ppm.tcool.org/server/ppmserver.cgi?urn:PPMServer
then you'll have yet another searchable ppm repository at hand.
And also I recommend to 'ppm rep up tcool' several times at the ppm shell. Other repositories with higher priority may be the cause of problems.