I already had a look in to this example perl application. I am on windows XP with Activeperl 5.10. For some reason, use Gtk2 qw/-init -threads-init/; crashes, I had to use only use Gtk2 qw/-init/; .
More over, Label update in this example application (which updates 1..2..3 in yellow color) stops update after 38 or 40 or some time after 50. So I would say this method is not reliable in Windows (atleast , need to check in Linux).
Also i wanted very fast gui updates, If you run my application you will see how fast it updates Text Buffers.