Unity crashes Xorg server

[IC Raibow]

After recent upgrade launching unity session causes Xorg server to crash with sigsegv. There's no metacity-based session to fallback to.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: xorg 1:7.7+1ubuntu3
ProcVersionSignature: Ubuntu 3.5.0-11.11-generic 3.5.2
Uname: Linux 3.5.0-11-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.5.1-0ubuntu2
Architecture: amd64
Date: Sat Aug 25 20:17:23 2012
DistUpgraded: Fresh install
DistroCodename: quantal
DistroVariant: ubuntu
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120724.2)
MachineType: Gigabyte Technology Co., Ltd. GA-870A-UD3
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-11-generic root=UUID=0b0b165a-8160-4aba-8f23-0fcc4470c257 ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/15/2010
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F1
dmi.board.name: GA-870A-UD3
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF1:bd04/15/2010:svnGigabyteTechnologyCo.,Ltd.:pnGA-870A-UD3:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnGA-870A-UD3:rvr:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: GA-870A-UD3
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
version.compiz: compiz 1:0.9.8+bzr3319-0ubuntu2
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.38-0ubuntu2
version.libgl1-mesa-dri: libgl1-mesa-dri 9.0~git20120821.c1114c61-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.0~git20120821.c1114c61-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.12.99.905-0ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.99.99~git20120713.6ef1ad6a-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.20.3-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.1-4~ubuntu1