And the call to use add_poly is like this ...

      # Add filled Triangle
      $PPT->add_polyline( {'points'    => [[$pptpoints[0], $pptpoints[
+1]], [$pptpoints[2], $pptpoints[3]], [$pptpoints[4], $pptpoints[5]], 
+[$pptpoints[0], $pptpoints[1]]],
                           'fillcolor' => &convert2RGBvalues($fill),
                           'weight'    => $weight/px2pt,
                           'forecolor' => &convert2RGBvalues($color) }
+);
[download]

Although, as I've said I've tried multiple variations of the list for 'points'

The net result is that my $new_poly never gets set and the next line that uses $new_poly says "Use of uninitialized value $new_poly" yet no errors are thrown.