I'm usually the one answering questions, but in this I'm throughly stumped!

My Setup:

Ubuntu 12.10 (Dist upgrade form 12.04) ATI M96 [Mobility Radeon HD 4650]

Upon the first installation of 12.10 I had all kinds of issues getting the Legacy ATI drivers to install (I guess the source for the drivers isn't kosher with kernel 3.5). So, I added the repository ppa:makson96/fglrx - which has a version of the ATI source patched to work with kernel 3.5. After installation of fglrx-legacy from that PPA, gnome-shell and all my graphics work fine... until today.

The Problem

I unsuspended my computer today and the screen was black (not off, the black from the gnome lock screen). I'd move my mouse/hit a key and the background would flash and then it'd go back to black.

Restarted via VT1

Logged into Gnome (gnome-shell) session, but no gnome-shell!

Investigation:

First, I went to VT1 and tried export DISPLAY=:0;gnome-shell --replace. It appeared to work fine, switch back to X and nothing. Went back to VT1 and saw this error message:

JS ERROR: !!!   Exception was: TypeError: Object 0x7fc748129c30 is not a subclass of (null), it's a xO
JS ERROR: !!!     message = '"Object 0x7fc748129c30 is not a subclass of (null), it's a xO"'
JS ERROR: !!!     fileName = '"/usr/share/gnome-shell/js/ui/tweener.js"'
JS ERROR: !!!     lineNumber = '218'
JS ERROR: !!!     stack = '"()@/usr/share/gnome-shell/js/ui/tweener.js:218
wrapper()@/usr/share/gjs-1.0/lang.js:204
()@/usr/share/gjs-1.0/lang.js:145
()@/usr/share/gjs-1.0/lang.js:239
init()@/usr/share/gnome-shell/js/ui/tweener.js:49
init()@/usr/share/gnome-shell/js/ui/environment.js:96
@<main>:1
"'
Window manager warning: Log level 32: Execution of main.js threw exception: TypeError: Object 0x7fc748129c30 is not a subclass of (null), it's a xO

Note: Everywhere it says "it's a xO", xO is actually garbled and changes every time (I'm thinking memory corruption?)

This error is thrown by line 96 of /usr/share/gnome-shell/js/ui/environment.js: tweener.Init()

Did a purge of fglrx-legacy, reboot, reinstall fglrx-legacy, reboot... same thing.

Did a ppa-purge of ppa:gnome3-team/gnome3, and reinstalled gnome-shell and ubuntu-desktop from the standard repositores... same thing.

I'm really at a loss here. I love gnome-shell and after using it for nearly a year now gnome classic just seems so archaic.

Additional Information

Apt log from the day I first suspended my machine (these are upgrades from the gnome3-team/gnome3 ppa and ubuntu-wine/ppa ppa):

Start-Date: 2012-11-24  17:30:28
Commandline: aptdaemon role='role-commit-packages' sender=':1.618'
Install: gkbd-capplet:amd64 (3.6.0-0ubuntu1), gnome-control-center-unity:amd64 (1.0-0ubuntu1~ubuntu12.10.1)
Upgrade: nautilus:amd64 (3.6.2-0ubuntu0.1~quantal1, 3.6.3-0ubuntu2~ubuntu12.10.1), libgnome-control-center1:amd64 (3.4.2-0ubuntu19, 3.6.3-0ubuntu6~ubuntu12.10.1), wine1.5-i386:i386 (1.5.17-0ubuntu4, 1.5.18-0ubuntu1), wine1.5:amd64 (1.5.17-0ubuntu4, 1.5.18-0ubuntu1), gnome-settings-daemon:amd64 (3.4.2-0ubuntu14, 3.6.3-0ubuntu1~ubuntu12.10.1), gnome-control-center-data:amd64 (3.4.2-0ubuntu19, 3.6.3-0ubuntu6~ubuntu12.10.1), gnome-accessibility-themes:amd64 (3.6.0.2-0ubuntu1, 3.6.2-0ubuntu2~ubuntu12.10.1), gnome-themes-standard:amd64 (3.6.0.2-0ubuntu1, 3.6.2-0ubuntu2~ubuntu12.10.1), wine1.5-amd64:amd64 (1.5.17-0ubuntu4, 1.5.18-0ubuntu1), nautilus-data:amd64 (3.6.2-0ubuntu0.1~quantal1, 3.6.3-0ubuntu2~ubuntu12.10.1), gnome-control-center:amd64 (3.4.2-0ubuntu19, 3.6.3-0ubuntu6~ubuntu12.10.1), libnautilus-extension1a:amd64 (3.6.2-0ubuntu0.1~quantal1, 3.6.3-0ubuntu2~ubuntu12.10.1)
End-Date: 2012-11-24  17:31:32

fglrxinfo (driver appears to be working):

display: :0  screen: 0
OpenGL vendor string: Advanced Micro Devices, Inc.
OpenGL renderer string: ATI Mobility Radeon HD 4650
OpenGL version string: 3.3.11653 Compatibility Profile Context

Does anybody have any further ideas?