I'm experiencing some problems with Ubuntu Gnome Remix 12.10 64bits.
My gnome-tweak-tool doesn't apply themes properly. For the gkt themes, I noted that they are not fully applied. For example, I select Elementary's gtk theme and the window's border (metacity?) still with Adwaita. The theme also looks weird, what led me to believe that there was some engine missing, but that wasn't the case.
The problem got bigger after a recent crash on my Gnome-shell, when I had to use the command gnome-shell --replace on Terminal to get my environment back. Now when I open gnome-tweak-tool, it doesn't display the option of changing shell theme (shows that icon as if I was on Unity or other stuff).
I don't know if this is consequence of any recent update, but I'm using Gnome-shell 3.6.1. I also have gnome3-team ppa installed.
I hope you understand my english :(