compiz crashed with SIGSEGV in pthread_mutex_lock()

Binary package hint: compiz

Installed AMD restricted driver for HD5770, upon restart Unity no longer loads and instead falls back upon Ubuntu Classic. Tried running unity from the Terminal and Compiz crashed, after several very bizarre graphical glitches.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: compiz-core 1:0.9.4git20110322-0ubuntu5
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
NonfreeKernelModules: fglrx
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,grid,imgpng,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,unitymtgrabhandles,scale,session,unityshell]
CompositorRunning: None
Date: Fri Apr 1 01:49:08 2011
DistUpgraded: Fresh install
DistroCodename: natty
DistroVariant: ubuntu
DkmsStatus: fglrx, 8.840, 2.6.38-7-generic, i686: installed
ExecutablePath: /usr/bin/compiz
GraphicsCard:
 ATI Technologies Inc Juniper [Radeon HD 5700 Series] [1002:68b8] (prog-if 00 [VGA controller])
   Subsystem: Hightech Information System Ltd. Device [1787:200a]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta i386 (20110330)
InstallationMedia_: Ubuntu 11.04 "Natty Narwhal" - Beta i386 (20110330)
JockeyStatus: xorg:fglrx - ATI/AMD proprietary FGLRX graphics driver (Proprietary, Enabled, In use)
Lsusb:
 Bus 002 Device 004: ID 045e:0040 Microsoft Corp. Wheel Mouse Optical
 Bus 002 Device 003: ID 413c:2010 Dell Computer Corp.
 Bus 002 Device 002: ID 413c:1003 Dell Computer Corp. Keyboard Hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: System manufacturer System Product Name
ProcCmdline: compiz --replace
ProcEnviron:
 LANGUAGE=en_GB:en
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic root=UUID=76ba2ec2-865a-489b-bfca-030ed75fe5be ro quiet splash vt.handoff=7
ProcVersionSignature_: Ubuntu 2.6.38-7.39-generic 2.6.38
Renderer: Unknown
SegvAnalysis:
 Segfault happened at: 0xe2133d <pthread_mutex_lock+29>: mov 0xc(%esi),%edi
 PC (0x00e2133d) ok
 source "0xc(%esi)" (0x0000000f) not located in a known VMA region (needed readable region)!
 destination "%edi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: compiz
StacktraceTop:
 pthread_mutex_lock () from /lib/i386-linux-gnu/libpthread.so.0
 ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
 Glib::Source::unreference() const () from /usr/lib/libglibmm-2.4.so.1
 PrivateScreen::~PrivateScreen() ()
 PrivateScreen::~PrivateScreen() ()
Title: compiz crashed with SIGSEGV in pthread_mutex_lock()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
XsessionErrors:
 (nautilus:1958): Gtk-WARNING **: Change Desktop Background: missing action Change Desktop Background
 (nautilus:1958): Gtk-WARNING **: Ubuntu Documentation: missing action Ubuntu Documentation
 (nautilus:1958): Gtk-WARNING **: Change Desktop Background: missing action Change Desktop Background
 (nautilus:1958): Gtk-WARNING **: Ubuntu Documentation: missing action Ubuntu Documentation
 (nautilus:1958): GConf-CRITICAL **: gconf_value_free: assertion `value != NULL' failed
dmi.bios.date: 10/21/2005
dmi.bios.vendor: Phoenix Technologies, LTD
dmi.bios.version: ASUS A8N-SLI Premium ACPI BIOS Revision 1009
dmi.board.name: A8N-SLI Premium
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: 1.02
dmi.chassis.asset.tag: 123456789000
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnPhoenixTechnologies,LTD:bvrASUSA8N-SLIPremiumACPIBIOSRevision1009:bd10/21/2005:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnA8N-SLIPremium:rvr1.02:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz 1:0.9.4git20110322-0ubuntu5
version.fglrx-installer: fglrx-installer N/A
version.libdrm2: libdrm2 2.4.23-1ubuntu5
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.1-0ubuntu3
version.xserver-xorg: xserver-xorg 1:7.6~3ubuntu11
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu6