Benchmark disk: Error opening /dev/sdb: Device or resource busy (udisks-error-quark, 0)

[florin]

There are many errors in working with USB (creating USB startup disk was the first to see) and now I cannot benchmark the USB drive as I get the Error opening /dev/sdb: Device or resource busy (udisks-error-quark, 0) error. I tried dozen of times, to make sure it is not something temporary. At some point I could do it on a different thumb drive, I do no know how, but after 2 errors, it worked. The second thumb drive was not that lucky.

There is some other bug, the one that I used before still appears in the list, see screenshot. It is not connected, but appears in Disks application drives list.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: udisks 1.0.4-7build1
ProcVersionSignature: Ubuntu 3.8.0-31.46-generic 3.8.13.8
Uname: Linux 3.8.0-31-generic x86_64
ApportVersion: 2.9.2-0ubuntu8.3
Architecture: amd64
CustomUdevRuleFiles: 50-compat_firmware.rules 10-vboxdrv.rules
Date: Tue Oct 8 15:38:35 2013
InstallationDate: Installed on 2013-04-25 (165 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MachineType: TOSHIBA Satellite C650
MarkForUpload: True
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.8.0-31-generic root=UUID=37650fee-4c1e-45ca-bb58-8625bd763023 ro quiet splash vt.handoff=7
SourcePackage: udisks
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/16/2011
dmi.bios.vendor: INSYDE
dmi.bios.version: 1.90
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Portable PC
dmi.board.vendor: TOSHIBA
dmi.board.version: Base Board Version
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Chassis Manufacturer
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnINSYDE:bvr1.90:bd03/16/2011:svnTOSHIBA:pnSatelliteC650:pvrPSC14E-00400MG5:rvnTOSHIBA:rnPortablePC:rvrBaseBoardVersion:cvnChassisManufacturer:ct10:cvrChassisVersion:
dmi.product.name: Satellite C650
dmi.product.version: PSC14E-00400MG5
dmi.sys.vendor: TOSHIBA