Gutters, backgrounds and flashing

One of the things that makes gutter flashing so annoying is that the repaint is done as follows. 1. Area is cleared using color OB 2. New buffer-tabs are painted. For me OB != background color. (I can get awfull flashing by simply dragging another X window over the buffer tabs, partially exposing it). It would be much better if 1. wasn't done but at least it should use the right color. For me OB is white. In site-start.el we have (set-face-background 'default "white") and in my ~/.xemacs/options.el I have (custom-set-faces '(default ((((type x) (class color)) (:background "lightyellow" :size "12pt" :family "Fixed"))) t) Why does it keep using the "old" background color "OB". Jan