Hmm so what happened is that you used desktop-swicher and that changed the GConf settings from "use the defaults" (Gtk+ theme and panel layout notably) to "user set". On upgrade, the defaults were changed but your "manually" set settings were kept as overrides.
(This is typically why we drop desktop-switcher and want to use separate session types which override the GConf path in next release.)
I guess we need some piece of code on upgrades which forces fixing the panel config, the gtk+ theme and the like when we detect that you one used desktop-switcher.
Hmm so what happened is that you used desktop-swicher and that changed the GConf settings from "use the defaults" (Gtk+ theme and panel layout notably) to "user set". On upgrade, the defaults were changed but your "manually" set settings were kept as overrides.
(This is typically why we drop desktop-switcher and want to use separate session types which override the GConf path in next release.)
I guess we need some piece of code on upgrades which forces fixing the panel config, the gtk+ theme and the like when we detect that you one used desktop-switcher.