Does not detect hotplugged storage device

[TheMad]

When i plug in my USB flash drive the system doesn't detect it even if it shows in lsusb

Bus 001 Device 008: ID 154b:6545 PNY FD Device
Bus 001 Device 002: ID 13d3:5702 IMC Networks UVC VGA Webcam
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: udev 175-0ubuntu9.2
Uname: Linux 3.6.4-pf-amd64 x86_64
ApportVersion: 2.0.1-0ubuntu14
Architecture: amd64
CustomUdevRuleFiles: 40-permissions.rules
Date: Sat Oct 27 18:53:45 2012
HotplugNewDevices: /dev/sdb /dev/sdb1
HotplugNewMounts:

InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: ASUSTeK Computer INC. 1215P
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.6.4-pf-amd64 root=UUID=fc8f23ce-d444-40d7-a462-3e977deffe56 ro
SourcePackage: udev
Symptom: storage
Title: Does not detect hotplugged storage device
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/18/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0601
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 1215P
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: x.xx
dmi.chassis.asset.tag: 0x00000000
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer INC.
dmi.chassis.version: x.x
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0601:bd04/18/2011:svnASUSTeKComputerINC.:pn1215P:pvrx.x:rvnASUSTeKComputerINC.:rn1215P:rvrx.xx:cvnASUSTeKComputerINC.:ct10:cvrx.x:
dmi.product.name: 1215P
dmi.product.version: x.x
dmi.sys.vendor: ASUSTeK Computer INC.