Comment 17 for bug 180132

The advanced login settings are indeed not saved if you enable auto-login; this is a known bug. If you manually log in, all works correctly AFAIK.

"I think the preferences.rdb file should be updated/saved immediately after pressing the save button in the profile editor, or when acknowleding on the login window."

+1. I also think it may be interesting to apply changes on-the-fly as in Gnome and Mac OS X (no Save button needed).