xserver crashed with segfault in RecordAReply

Binary package hint: xserver-xorg-video-intel

Xserver frequently crashes when I start calibre and switch between different ebooks in the ebook list.
This crash is quite reproducible, about 80% of the times I run calibre. The crash happens both in unity and in classic desktop session, but only when compiz is active. When I switch of sync to vblank in compiz, the crash does not happen.
Attached is a full stacktrace. It looks like the client does not have a reference to the X request when the X reply is processed in RecordAReply.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: xserver-xorg-video-intel 2:2.14.0-4ubuntu7.1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,grid,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,scale,session,unityshell]
CompositorRunning: compiz
DRM.card0.LVDS.1:
 status: connected
 enabled: enabled
 dpms: On
 modes: 1280x800
 edid-base64: AP///////wAyDADbAAAAAAAQAQOAIRV4CrNAmVlTjSclUFQAAAABAQEBAQEBAQEBAQEBAQEBvBsAoFAgFzAwIDYAS88QAAAZAAAAAAAAAAAAAAAAAAAAAAAAAAAA/gBMR1BoaWxpcHNMQ0QKAAAA/gBMUDE1NFdYNC1UTEMxAEY=
DRM.card0.VGA.1:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
Date: Tue May 3 23:46:18 2011
DistUpgraded: Log time: 2011-02-20 16:09:31.871558
DistroCodename: natty
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) [8086:2a02] (rev 0c) (prog-if 00 [VGA controller])
   Subsystem: COMPAL Electronics Inc Device [14c0:0026]
   Subsystem: COMPAL Electronics Inc Device [14c0:0026]
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Alpha amd64 (20100630.2)
MachineType: - N/A
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: root=/dev/mapper/hostname-natty ro quiet noresume enable_mtrr_cleanup
Renderer: Unknown
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: Upgraded to natty on 2011-02-20 (72 days ago)
dmi.bios.date: 06/26/2007
dmi.bios.vendor: COMPAL
dmi.bios.version: 1.10
dmi.board.name: IFL91
dmi.board.vendor: COMPAL
dmi.board.version: REFERENCE
dmi.chassis.asset.tag: -
dmi.chassis.type: 10
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnCOMPAL:bvr1.10:bd06/26/2007:svn-:pnN/A:pvrN/A:rvnCOMPAL:rnIFL91:rvrREFERENCE:cvnNoEnclosure:ct10:cvrN/A:
dmi.product.name: N/A
dmi.product.version: N/A
dmi.sys.vendor: -
version.compiz: compiz 1:0.9.4+bzr20110415-0ubuntu2
version.ia32-libs: ia32-libs 20090808ubuntu13
version.libdrm2: libdrm2 2.4.23-1ubuntu6
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.2-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.2-0ubuntu2
version.xserver-xorg: xserver-xorg 1:7.6+4ubuntu3
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu7.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7