Description of problem: We should deactivate /etc/xdg/autostart/xfconf-migration-4.6.desktop on the live cd because in live mode there is nothing to migrate and the dialog for migrating the panel sucks. Version-Release number of selected component (if applicable): F15 Xfce
Fixed in http://git.fedorahosted.org/git/?p=spin-kickstarts.git;a=commit;h=02d9311192fa1339d807fbbc82729be1ef4323ff and should be available in the next nightly and F15 Beta TC2.