Fixed the problem by going to a brand new, empty, home directory. I
think the many dotfiles and "dotdirs" created by gnome, gtk and friends
must have a way of going bad with time. I would guess that it happened
when I upgraded from SUSE 10.0 to 10.1.
I updated bug 346588 and unless this is all a dream, I suppose it can
now be closed. It is still strange that I only got the segfault with
Comcast and giganews, but that will most likely never be explained.