Xorg crashed with SIGABRT in RRCrtcDetachScanoutPixmap()

I just try current Saucy build, and got this error when loading completed.
X still continue working. May be logs will help you to fix it...

I am using acer 4820tg.

ProblemType: Crash
DistroRelease: Ubuntu 13.10
Package: xserver-xorg-core 2:1.13.3-0ubuntu13
ProcVersionSignature: Ubuntu 3.9.0-6.14-generic 3.9.6
Uname: Linux 3.9.0-6-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.10.2-0ubuntu2
Architecture: amd64
CasperVersion: 1.333
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Tue Jun 25 03:36:58 2013
DistUpgraded: Fresh install
DistroCodename: saucy
DistroVariant: ubuntu
ExecutablePath: /usr/bin/Xorg
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 18) (prog-if 00 [VGA controller])
   Subsystem: Acer Incorporated [ALI] Device [1025:0359]
 Advanced Micro Devices, Inc. [AMD/ATI] Madison [Mobility Radeon HD 5650/5750 / 6530M/6550M] [1002:68c1] (prog-if 00 [VGA controller])
   Subsystem: Acer Incorporated [ALI] Mobility Radeon HD 5650 [1025:0359]
LiveMediaBuild: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130624)
MachineType: Acer Aspire 4820TG
MarkForUpload: True
ProcCmdline: X -br -ac -noreset -nolisten tcp -background none vt7 :0
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 LANG=en_US.UTF-8
ProcKernelCmdLine: noprompt cdrom-detect/try-usb=true persistent file=/cdrom/preseed/hostname.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 RRCrtcDetachScanoutPixmap ()
 ?? ()
 ?? ()
 ?? ()
 ?? ()
Title: Xorg crashed with SIGABRT in RRCrtcDetachScanoutPixmap()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

dmi.bios.date: 03/16/2011
dmi.bios.vendor: INSYDE
dmi.bios.version: V1.25
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: JM41_CP
dmi.board.vendor: Acer
dmi.board.version: Base Board Version
dmi.chassis.type: 10
dmi.chassis.vendor: Chassis Manufacturer
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnINSYDE:bvrV1.25:bd03/16/2011:svnAcer:pnAspire4820TG:pvrV1.25:rvnAcer:rnJM41_CP:rvrBaseBoardVersion:cvnChassisManufacturer:ct10:cvrChassisVersion:
dmi.product.name: Aspire 4820TG
dmi.product.version: V1.25
dmi.sys.vendor: Acer
version.compiz: compiz 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.45-2ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.1.3-0ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.1.3-0ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3-0ubuntu13
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.9-0ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.8-0ubuntu1
xserver.bootTime: Tue Jun 25 03:37:01 2013
xserver.configfile: default
xserver.errors: RADEON(G0): [XvMC] Failed to initialize extension.
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.13.3-0ubuntu13
xserver.video_driver: intel