Regarding gconftool:

I tried it as root and as 'user'. Still getting the segfault. I'm not going to reflash my 770 though, it's such a pain in the butt to get all the little settings and apps back on it. I'll sit back and wait until things become more stable.

BTW, there is no /apps/maemo or even /apps on my machine, so maybe that has something to do with it. And I have no idea what 'gconftool-2' is! Does anyone know the directories/files that are involved in the mapper settings? I'd be happy to delete them by hand rather than trying some script or tool to do it - gconftool doesn't give any feedback.