Right, those should be disabled in the SDK. I will have a look at this.
But there is another problem with using a stock button, in that it doesn't adopt the right themeing by default. I would suggest to use hildon_button_new (HILDON_SIZE_FINGER_HEIGHT, ..) (or hildon_gtk_button_new), but if you want to keep using the stock ID, then you should manually call hildon_gtk_widget_set_theme_size() after creating the button.