Here's my test code:

#!/usr/bin/perl
use strict;
use Win32::GUI;

my $mw = new Win32::GUI::Window (
 -title    => "test",
 -pos      => [600, 600],
 -size     => [100, 100],
 -name     => "Window",
);
my $tooltip1 = Win32::GUI::Tooltip->new( -parent => $mw,
                                         -name   => "tooltip1",
                                       );
$tooltip1->AddTool( -window => $mw,
                    -text   => "Text that pops up",
                  );
$tooltip1->Activate();
$mw->Show();
Win32::GUI::Dialog();

sub Window_Terminate { -1 }

This should generate a simple tooltip when I hover the mouse over the main window, yet nothing happens. I'm not sure what I am missing here. ;_;