Can I use gtk_widget_unref() to releasetthe object created by gtk_invisible_new()?

[Brian Lu <Brian Lu Sun COM>]

Hi, experts,

I found following codes will crash in gnome 2.21 environment:

 ...
 GtkWidget *foo = gtk_invisible_new();
 gtk_widget_unref(foo);
 ...

But it works well if gtk_widget_unref() is replaced with 
gtk_widget_destroy().

Does that mean that we can't use gtk_widget_unref() on such object and 
we can only
use gtk_widget_destroy() to release it?

Thanks

Brian