The F15 Gnome 3 live image that was released on May 24 would not
save changes with a persistent overlay so maybe the F15 LXDE spin
was also affected by the no persistence "bug".
What I did was use the "livecd-creator" tool to create a new F15 Gnome 3
spin with the latest updates and with the persistent overlay changes are
saved across reboots. I'm currently creating a F15 LXDE spin and will
see if the persistence works and save changes. Will report back as soon
as the d'load completes and it is installed to usb and tested.
phil