See http://bugzilla.gnome.org/show_bug.cgi?id=63480 Refiled here to mark as Milan Target and blocker for an anaconda workaround.
Note that any fix is probably going to involve an API change, since the GtkScrolledWindow has no idea when it shoudl reserve space for focus indication and also a UI decision about how it is drawn; so not going to happen in the GTK+-2.2 timeframe.
I've worked around it in anaconda anyway
Untargetting, blockering; nothing more is going to be done for GTK+-2.2.x.
Marking various no-need-to-be-private bugs public.