Engine detecting problem. about pdl-graphics-simple HOT 4 CLOSED

pdl> use PDL::Graphics::Simple;

pdl> $w=pgswin(engine=>'PGPLOT'); # should fail  <-- Can't see any error message

pdl> print $PDL::Graphics::Simple::mods->{pgplot}->{msg};
Use of uninitialized value in print at (eval 472) line 5, <IN> line 3.

pdl> use PDL::Graphics::PGPLOT::Window

pdl> $win = pgwin();

pdl> $win->line([1,2,3],[1,2,3])

--- C:\strawberry-perl-5.16.3.1-32bit\perl\site\lib\PDL\Graphics\Simple\PGPLOT.pm.org   Tue Mar 26 07:29:04 2013
+++ C:\strawberry-perl-5.16.3.1-32bit\perl\site\lib\PDL\Graphics\Simple\PGPLOT.pm       Wed Mar 27 16:37:13 2013
@@ -63,6 +63,10 @@
        $mod->{disp_dev} = 'XWINDOW';
     } elsif($mod->{devices}->{'XSERVE'} ) {
        $mod->{disp_dev} = 'XSERVE';
+    } elsif($mod->{devices}->{'CGW'} ) {
+        $mod->{disp_dev} = 'CGW';
+    } elsif($mod->{devices}->{'GW'} ) {
+        $mod->{disp_dev} = 'GW';
     } else {
        $mod->{ok} = 0;
        return 0;