kernel BUG at /build/buildd/linux-2.6.38/fs/ecryptfs/crypto.c:349!; EIP is at encrypt_scatterlist+0xe4/0x120

Left the computer on all night with the power setting to shut down monitor. When I came back next morning to work on it some more the first thing on screen when the monitor energized was that there had been a crash......which I am now reporting.

ProblemType: KernelOops
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.42
Regression: Yes
Reproducible: No
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
NonfreeKernelModules: nvidia
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Annotation: Your system might become unstable now and might need to be restarted.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: I82801BAICH2 [Intel 82801BA-ICH2], device 0: Intel ICH [Intel 82801BA-ICH2]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: mtech 1543 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'I82801BAICH2'/'Intel 82801BA-ICH2 with AD1885 at irq 17'
   Mixer name : 'Analog Devices AD1885'
   Components : 'AC97a:41445360'
   Controls : 36
   Simple ctrls : 26
Date: Fri Apr 15 23:03:28 2011
Failure: oops
Frequency: This has only happened once.
HibernationDevice: RESUME=UUID=4e361787-1488-418c-93df-eefa856a90b7
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110329.1)
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.
Lsusb:
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: Dell Computer Corporation Precision WorkStation 530 MT
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=ff9cfdcc-5be1-4991-9b52-9a755845758d ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-8-generic N/A
 linux-backports-modules-2.6.38-8-generic N/A
 linux-firmware 1.50
RfKill:

SourcePackage: linux
Title: kernel BUG at /build/buildd/linux-2.6.38/fs/ecryptfs/crypto.c:349!
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/01/2004
dmi.bios.vendor: Dell Computer Corporation
dmi.bios.version: A11
dmi.board.vendor: Dell Computer Corp.
dmi.chassis.type: 6
dmi.chassis.vendor: Dell Computer Corporation
dmi.modalias: dmi:bvnDellComputerCorporation:bvrA11:bd11/01/2004:svnDellComputerCorporation:pnPrecisionWorkStation530MT:pvr:rvnDellComputerCorp.:rn:rvr:cvnDellComputerCorporation:ct6:cvr:
dmi.product.name: Precision WorkStation 530 MT
dmi.sys.vendor: Dell Computer Corporation