$there is no longer a GSignal !!
#Gtk2::GSignal->connect( $button_poll, "clicked", \&poll_host ); 
#Gtk2::GSignal->connect( $button_exit, "clicked", \&exit_app );
#SHOULD BE 
$button_poll->signal_connect("clicked", \&poll_host );
$button_exit->signal_connect("clicked", \&exit_app );