I also have this problem. I reported it as bug #70046, which is a duplicate I guess. Anyway here's a backtrace from bug-buddy.
** Attachment added: "Debug backtrace from bug-buddy" http://librarian.launchpad.net/5067490/gnome-settings-daemon-bugreport.txt -- gnome-settings-daemon crashes at login https://launchpad.net/bugs/61381 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
