Comment 0 for bug 1082920

Reproduced this bug on "Daily Build" live cd:
http://cdimage.ubuntu.com/precise/daily/current/

Plug in the USB stick: (DMESG)
[ 354.732093] usb 2-1: new high-speed USB device number 3 using ehci_hcd
[ 354.907701] Initializing USB Mass Storage driver...
[ 354.907892] scsi6 : usb-storage 2-1:1.0
[ 354.908037] usbcore: registered new interface driver usb-storage
[ 354.908040] USB Mass Storage support registered.
[ 354.909714] usbcore: registered new interface driver uas
[ 355.929718] scsi 6:0:0:0: Direct-Access Kingston DataTraveler 108 PMAP PQ: 0 ANSI: 0 CCS
[ 355.930970] sd 6:0:0:0: Attached scsi generic sg2 type 0
[ 356.706843] sd 6:0:0:0: [sdb] 15646720 512-byte logical blocks: (8.01 GB/7.46 GiB)
[ 356.708571] sd 6:0:0:0: [sdb] Write Protect is off
[ 356.708577] sd 6:0:0:0: [sdb] Mode Sense: 03 41 00 00
[ 356.710320] sd 6:0:0:0: [sdb] No Caching mode page present
[ 356.710326] sd 6:0:0:0: [sdb] Assuming drive cache: write through
[ 356.716318] sd 6:0:0:0: [sdb] No Caching mode page present
[ 356.716325] sd 6:0:0:0: [sdb] Assuming drive cache: write through
[ 356.733983] sdb: sdb1
[ 356.739312] sd 6:0:0:0: [sdb] No Caching mode page present
[ 356.739317] sd 6:0:0:0: [sdb] Assuming drive cache: write through
[ 356.739321] sd 6:0:0:0: [sdb] Attached SCSI removable disk

(System created sdb,sdb1 files, and mounted sdb1 filesystem correctly)

I click the "Eject" command on USB stick with the GUI.(I want only unmount the sdb1 filesystem)
Unexcepted message(DMESG):
[ 606.780774] sdb: detected capacity change from 8011120640 to 0

Try:
ubuntu@ubuntu:~$ ls /dev/sdb*
/dev/sdb

"sdb1" is missing! Usb stick is useless until plug it in again.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-34-generic 3.2.0-34.53
ProcVersionSignature: Ubuntu 3.2.0-34.53-generic 3.2.33
Uname: Linux 3.2.0-34-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC270 Analog [ALC270 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
ApportVersion: 2.0.1-0ubuntu15
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC270 Analog [ALC270 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: ubuntu 3195 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xd4500000 irq 45'
   Mixer name : 'Realtek ALC270'
   Components : 'HDA:10ec0270,103c1605,00100100'
   Controls : 18
   Simple ctrls : 10
CasperVersion: 1.315
Date: Sun Nov 25 16:28:21 2012
LiveMediaBuild: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release amd64 (20121125)
MachineType: Hewlett-Packard Presario CQ56 Notebook PC
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=(loop)/casper/vmlinuz iso-scan/filename=/precise-desktop-amd64.iso root=(hd0,2) boot=casper quiet splash
RelatedPackageVersions:
 linux-restricted-modules-3.2.0-34-generic N/A
 linux-backports-modules-3.2.0-34-generic N/A
 linux-firmware 1.79.1
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/07/2011
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: F.15
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 1605
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 90.17
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnHewlett-Packard:bvrF.15:bd04/07/2011:svnHewlett-Packard:pnPresarioCQ56NotebookPC:pvr059D110000002810010000000:rvnHewlett-Packard:rn1605:rvr90.17:cvnHewlett-Packard:ct10:cvrN/A:
dmi.product.name: Presario CQ56 Notebook PC
dmi.product.version: 059D110000002810010000000
dmi.sys.vendor: Hewlett-Packard