Xorg crashed with SIGSEGV in valuator_mask_set_double

#0 valuator_mask_set_double (mask=0x31, valuator=4, data=570) at ../../dix/inpututils.c:509
No locals.
#1 0xb76564eb in valuator_mask_set (mask=0x31, valuator=4, data=570) at ../../dix/inpututils.c:520
No locals.
#2 0xb33398ab in EventProcessTouchEvent (hw=0xb86ca4f0, pInfo=0xb8671298, ev=<optimized out>) at ../../src/eventcomm.c:579
        map = 4
        slot_index = -1
        priv = 0xb86c3388
        proto_data = 0xb86bc550
#3 EventReadHwState (pInfo=0xb8671298, comm=0xb86c3518, hwRet=0xb86c9848) at ../../src/eventcomm.c:730
        ev = {time = {tv_sec = 1331109901, tv_usec = 814732}, type = 3, code = 48, value = 570}
        v = <optimized out>
        hw = 0xb86ca4f0
        priv = 0xb86c3388
        para = 0xb86c3388
        proto_data = 0xb86bc550
#4 0xb3332872 in SynapticsGetHwState (hw=0xb86c9848, priv=0xb86c3388, pInfo=0xb8671298) at ../../src/synaptics.c:1576
No locals.
#5 ReadInput (pInfo=0xb8671298) at ../../src/synaptics.c:1592
        priv = 0xb86c3388
        hw = 0xb86c9848
        delay = 0
        newDelay = 0
#6 0xb767c151 in xf86SigioReadInput (fd=60, closure=0xb8671298) at ../../../../hw/xfree86/common/xf86Events.c:298
        errno_save = 0
        pInfo = 0xb8671298
#7 0xb76a3b48 in xf86SIGIO (sig=29) at ../../../../../hw/xfree86/os-support/linux/../shared/sigio.c:109
        i = <optimized out>
        ready = {fds_bits = {0, 268435456, 0 <repeats 30 times>}}
        to = {tv_sec = 0, tv_usec = 0}
        save_errno = 0
        r = 1
#8 <signal handler called>
No symbol table info available.
#9 0xb75e1424 in __kernel_vsyscall ()
No symbol table info available.
#10 0xb732a75d in ___newselect_nocancel () at ../sysdeps/unix/syscall-template.S:82
No locals.
#11 0xb778929c in WaitForSomething (pClientsReady=0xb866e6d8) at ../../os/WaitFor.c:232
        i = <optimized out>
        waittime = {tv_sec = 0, tv_usec = 139151}
        wt = 0xbf851dd4
        timeout = <optimized out>
        clientsReadable = {fds_bits = {0 <repeats 32 times>}}
        clientsWritable = {fds_bits = {9994, 236808, -1220639632, -1220639624, -1081795472, 236800, -1218238590, -1202050256, 236824, 462, 57, 7, -1216380940, -1081795296, -1217472199, -1203264348, -1203264344, 1, 8390865, -1216380940, -1216304112, -1202050256, -1217954880, -1202050256, -1199754792, -1203264348, 28, -1216380940, 1, -1220639680, -1216380940, 0}}
        selecterr = <optimized out>
        nready = 0
        devicesReadable = {fds_bits = {1, -1081795208, -1221421490, -1216343576, 0, -1081795296, -1216380940, -1216380940, 0, 32, -1216790850, 32, -1081795208, 1, -1217479194, -1216343576, -1081795296, -1216380940, -1216781137, -1199746120, -1081795208, 1, -1203273880, 0, -1221089459, -1219422347, -1216811360, -1199746120, -1081795208, 1, -1218054939, 2}}
        now = <optimized out>
        someReady = <optimized out>

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: xserver-xorg-core 2:1.11.4-0ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-18.28-generic-pae 3.2.9
Uname: Linux 3.2.0-18-generic-pae i686
NonfreeKernelModules: wl
ApportVersion: 1.94-0ubuntu2
Architecture: i386
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Wed Mar 7 15:45:01 2012
DistUpgraded: Log time: 2012-01-13 23:13:05.060884
DistroCodename: precise
DistroVariant: ubuntu
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: Yes, whatever it takes to get this fixed in Ubuntu
GraphicsCard:
 NVIDIA Corporation C79 [GeForce 9400M] [10de:0863] (rev b1) (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00ba]
MachineType: Apple Inc. MacBookPro5,4
ProcCmdline: /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
ProcEnviron:

ProcKernelCmdLine: root=UUID=e82d9a35-caee-4503-8594-8cd1eb26eec9 ro quiet splash
SegvAnalysis:
 Segfault happened at: 0xb765648b <valuator_mask_set_double+27>: movsbl (%eax),%ecx
 PC (0xb765648b) ok
 source "(%eax)" (0x00000031) not located in a known VMA region (needed readable region)!
 destination "%ecx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: xorg-server
StacktraceTop:
 ___newselect_nocancel () at ../sysdeps/unix/syscall-template.S:82
 WaitForSomething ()
 ?? ()
 ?? ()
 __libc_start_main (main=0xb7628f00, argc=8, ubp_av=0xbf851f54, init=0xb779b8c0 <__libc_csu_init>, fini=0xb779b930 <__libc_csu_fini>, rtld_fini=0xb75f1280 <_dl_fini>, stack_end=0xbf851f4c) at libc-start.c:226
Title: Xorg crashed with SIGSEGV in ___newselect_nocancel()
UnitySupportTest:
 Error: command ['/usr/lib/nux/unity_support_test', '-p', '-f'] failed with exit code 5: Xlib: extension "GLX" missing on display ":0".
 Error: GLX is not available on the system
UpgradeStatus: Upgraded to precise on 2012-01-14 (52 days ago)
UserGroups:

dmi.bios.date: 06/15/09
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP53.88Z.00AC.B03.0906151647
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-F22587A1
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro5,4
dmi.chassis.asset.tag: Asset Tag#
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F22587A1
dmi.modalias: dmi:bvnAppleInc.:bvrMBP53.88Z.00AC.B03.0906151647:bd06/15/09:svnAppleInc.:pnMacBookPro5,4:pvr1.0:rvnAppleInc.:rnMac-F22587A1:rvrMacBookPro5,4:cvnAppleInc.:ct10:cvrMac-F22587A1:
dmi.product.name: MacBookPro5,4
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz 1:0.9.7.0~bzr2995-0ubuntu5
version.libdrm2: libdrm2 2.4.30-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.1-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental 8.0.1-0ubuntu2
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.1-0ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.99.901+git20120126-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2