Hmm http://trouchelle.com/ppm/DBD-Pg.ppd lists http://trouchelle.com/ppm/scripts/installdll_dbdpg which lists

  {
   'lib'       => 'libintl3.dll ',
   'version'   => '0.14.4.1952',
   'size'      => '103423',
   'size_comp' => '52031',
  },
[download]

among others, did this program run when you installed DBD-Pg and did you install these files?