Comment 12 for bug 400863

I've made a patch that caches the result of ck-history so there is no delay on startup (patch also upstream):
lp:~ubuntu-desktop/gdm/ubuntu

The cached version is used on startup and then updated once ck-history completes. The information is only used for ordering the user list so out-of-date information should not cause any serious problems. The first startup will be delayed until the cache has been written to.