Why does scribble-simple.c's expose_event handler return false?

[re2824 SAFe-mail net]

Hi all.

Excuse me, but I'm a newbie to gtk. I understand scribble-simple.c (well, mostly) but I don't understand why 1 of the 4 event handlers returns false. I know that the return value from the event handler is supposed to indicate whether you want the event to be considered as "handled" (dealt with) by that handler. The configure_event, button_press_event and motion_notify_event handlers all return true. But why does the expose_event handler return false?

Enquiring minds and all that...

Thank you,

Jaime :-)