BUG: Bad page map in process Xorg pte:00010101 pmd:b7451067

I got this bug after looging into Ubuntu Natty Narwhal beta. I don't know what happened, I just love Ubuntu and Unity. Keep up the great work.

ProblemType: KernelOops
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-7-generic 2.6.38-7.39
Regression: Yes
Reproducible: No
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Annotation: Your system might become unstable now and might need to be restarted.
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: derrty 1403 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xd6400000 irq 42'
   Mixer name : 'Intel IbexPeak HDMI'
   Components : 'HDA:14f15069,1179fd50,00100302 HDA:80862804,1179fd50,00100000'
   Controls : 12
   Simple ctrls : 6
Date: Tue Apr 5 11:40:58 2011
Failure: oops
Frequency: Once a day.
HibernationDevice: RESUME=UUID=d881a30b-5483-4cd6-b4ce-b49b1c1deb73
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110302)
MachineType: TOSHIBA Satellite L655
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic root=UUID=0bd64942-0201-411a-b65e-5f36f8df961a ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-7-generic N/A
 linux-backports-modules-2.6.38-7-generic N/A
 linux-firmware 1.49
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Title: BUG: Bad page map in process Xorg pte:00010101 pmd:b7451067
UpgradeStatus: Upgraded to natty on 2011-03-29 (8 days ago)
dmi.bios.date: 12/31/2010
dmi.bios.vendor: INSYDE
dmi.bios.version: 1.90
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Base Board Product Name
dmi.board.vendor: Intel Corp.
dmi.board.version: Base Board Version
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: OEM Chassis Manufacturer
dmi.chassis.version: OEM Chassis Version
dmi.modalias: dmi:bvnINSYDE:bvr1.90:bd12/31/2010:svnTOSHIBA:pnSatelliteL655:pvrPSK2CU-0QU01U:rvnIntelCorp.:rnBaseBoardProductName:rvrBaseBoardVersion:cvnOEMChassisManufacturer:ct10:cvrOEMChassisVersion:
dmi.product.name: Satellite L655
dmi.product.version: PSK2CU-0QU01U
dmi.sys.vendor: TOSHIBA