[i945GM] Compositing conflicting with tablet features

Not having compositing activated, ubuntu or xubuntu, the tablet features (i.e. pen) works out of the box. Activating compositing, pen still works. X restarts, having compositing activated, pen stops working. With stops working, I mean the pointer falls into the right lower corner independently of where I use the pen.

I can deactivate compositing, restart X, then the pen works again. Temporary solution is to deactivate compositing on logout, and reactivate it on log in to have full tablet support.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: xorg 1:7.5+5ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-23.37-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-23-generic i686
Architecture: i386
Date: Sat Jul 17 23:31:46 2010
DkmsStatus: Error: [Errno 2] No such file or directory
EcryptfsInUse: Yes
GdmLog2:

InstallationMedia: Xubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100427.1)
MachineType: FUJITSU SIEMENS LIFEBOOK T4210
PccardctlIdent:
 Socket 0:
   no product info available
 Socket 1:
   product info: "O2Micro", "SmartCardBus Reader", "V1.0", ""
   manfid: 0xffff, 0x0001
PccardctlStatus:
 Socket 0:
   no card
 Socket 1:
   5.0V 16-bit PC Card
   Subdevice 0 (function 0) [unbound]
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.32-23-generic root=/dev/mapper/hostname-root ro quiet splash
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
dmi.bios.date: 05/10/2006
dmi.bios.vendor: FUJITSU // Phoenix Technologies Ltd.
dmi.bios.version: Version 1.02
dmi.board.name: FJNB1B9
dmi.board.vendor: FUJITSU
dmi.board.version: CP291221-01
dmi.chassis.type: 10
dmi.chassis.vendor: FUJITSU SIEMENS
dmi.chassis.version: T42__
dmi.modalias: dmi:bvnFUJITSU//PhoenixTechnologiesLtd.:bvrVersion1.02:bd05/10/2006:svnFUJITSUSIEMENS:pnLIFEBOOKT4210:pvr:rvnFUJITSU:rnFJNB1B9:rvrCP291221-01:cvnFUJITSUSIEMENS:ct10:cvrT42__:
dmi.product.name: LIFEBOOK T4210
dmi.sys.vendor: FUJITSU SIEMENS
glxinfo: Error: [Errno 2] No such file or directory
system:
 distro: Ubuntu
 codename: lucid
 architecture: i686
 kernel: 2.6.32-23-generic

[lspci]
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller [8086:27a2] (rev 03)
     Subsystem: Fujitsu Limited. Device [10cf:1380]