Session not being preserved across reboot?

[Paul Smith]

Hi all.

I have a strange situation that maybe someone can help with.  Originally
when I installed Ubuntu GNOME 14.04 (64bit; from-scratch installation)
it was fine.

But since a few weeks or so, every time I reboot my GNOME session loses
information about the extensions that I have enabled and reverts to the
default desktop, and I have to re-enable my extensions.  Then if I
reboot it resets again and I have to re-enable them again.

I'm using GNOME Tweak Tool to manage my extensions.

The only extensions I'm enabling are Frippery panel favorites and Window
List, so it's not like I have a ton of things, and I don't reboot that
often of course, but it's still annoying.

Thoughts?  I'm not sure where these settings are kept.