chiave USB non riconosciuta

[agenteo]

Ciao,
oggi mi è successa una cosa strana, Linux ubuntu non è stato in grado di 
accedere ad una memoria USB. In parole povere non appare l'icona sda 
come al solito.
Questo è il log:

Dec  2 09:47:49 prometeo kernel: usb 4-5: new high speed USB device 
using addres s 2
Dec  2 09:47:50 prometeo kernel: Initializing USB Mass Storage driver...
Dec  2 09:47:50 prometeo kernel: scsi0 : SCSI emulation for USB Mass 
Storage dev ices
Dec  2 09:47:50 prometeo kernel:   Vendor: Kingston  Model: DataTraveler 
2.0  Re v: 1.00
Dec  2 09:47:50 prometeo kernel:   Type:   
Direct-Access                      AN SI SCSI revision: 02
Dec  2 09:47:50 prometeo usb.agent[4936]:      usb-storage: loaded 
successfully
Dec  2 09:47:50 prometeo kernel: usbcore: registered new driver usb-storage
Dec  2 09:47:50 prometeo kernel: USB Mass Storage support registered.
Dec  2 09:47:50 prometeo scsi.agent[4993]: disk at 
/devices/pci0000:00/0000:00:0 3.3/usb4/4-5/4-5:1.0/host0/0:0:0:0
Dec  2 09:47:50 prometeo kernel: SCSI device sda: 974848 512-byte hdwr 
sectors ( 499 MB)
Dec  2 09:47:50 prometeo kernel: sda: Write Protect is off
Dec  2 09:47:50 prometeo kernel:  /dev/scsi/host0/bus0/target0/lun0: 
[CUMANA/ADF S] p1<5>Attached scsi removable disk sda at scsi0, channel 
0, id 0, lun 0
Dec  2 09:47:51 prometeo kernel: VFS: Can't find a valid FAT filesystem 
on dev s da1.
Dec  2 09:47:51 prometeo kernel: udf: registering filesystem
Dec  2 09:47:51 prometeo kernel: UDF-fs: No partition found (1)
Dec  2 09:47:51 prometeo kernel: Unable to identify CD-ROM format.
Dec  2 09:47:51 prometeo kernel: HFS+-fs: unable to find HFS+ superblock
Dec  2 09:47:51 prometeo kernel: VFS: Can't find a HFS filesystem on dev 
sda1.
Dec  2 09:47:51 prometeo kernel: VFS: Can't find ext2 filesystem on dev 
sda1.
Dec  2 09:47:51 prometeo kernel: ReiserFS: sda1: warning: sh-2021: 
reiserfs_fill _super: can not find reiserfs on sda1
Dec  2 09:47:51 prometeo kernel: SGI XFS with ACLs, security attributes, 
realtim e, large block numbers, no debug enabled
Dec  2 09:47:51 prometeo kernel: SGI XFS Quota Management subsystem
Dec  2 09:47:51 prometeo kernel: XFS: bad magic number
Dec  2 09:47:51 prometeo kernel: XFS: SB validate failed

mi sembra che non trovi un valido filesystem sulla chiave. Windows la 
apre senza problemi. Non sò come sia stata formattata... presumo vfat... 
forse ntfs? Ho provato a forzare il mount da root con -t (con vfat) ma 
mi diceva che il filesystem non era valido.
Mi sapreste dare un aiuto?
Grazie,
Enrico