Cita:
Iniciado por ociomax 
¿Qué versión de Debian? ¿Qué versión del kernel? ¿Estás usando HAL y udev? ¿Qué te dice el comando "dmesg" después de conectar el pendrive?
El comando dmesg informa lo siguiente :
# dmesg
...
usbcore: registered new driver usbfs
usbcore: registered new driver hub
USB Universal Host Controller Interface driver v2.3
...
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
...
uhci_hcd 0000:00:1d.2: UHCI Host Controller
uhci_hcd 0000:00:1d.2: new USB bus registered, assigned bus number 3
uhci_hcd 0000:00:1d.2: irq 185, io base 0x00001480
hub 3-0:1.0: USB hub found
hub 3-0:1.0: 2 ports detected
...
PCI: cache line size of 128 is not supported by device 0000:00:1d.7
ehci_hcd 0000:00:1d.7: new USB bus registered, assigned bus number 4
ehci_hcd 0000:00:1d.7: irq 193, io mem 0xfc480000
ehci_hcd 0000:00:1d.7: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004
hub 4-0:1.0: USB hub found
hub 4-0:1.0: 8 ports detected
hub 4-0:1.0: over-current change on port 7
.....
scsi0 : ata_piix
ata2: SATA port has no device.
scsi1 : ata_piix
....
Probing IDE interface ide0...
hda: ST340017A, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
Probing IDE interface ide1...
hdc: LTN486S, ATAPI CD/DVD-ROM drive
ide1 at 0x170-0x177,0x376 on irq 15
hda: max request size: 128KiB
hda: 78165360 sectors (40020 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100)
hda: cache flushes supported
hda: hda1 hda2 < hda5 > hda3 hda4
hdc: ATAPI 48X CD-ROM drive, 120kB Cache, DMA
....
usb 4-5: new high speed USB device using ehci_hcd and address 2
Initializing USB Mass Storage driver...
scsi2 : SCSI emulation for USB Mass Storage devices
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
usb-storage: device found at 2
usb-storage: waiting for device to settle before scanning
Vendor: VBTM Model: Store 'n' Go Rev: 5.00
Type: Direct-Access ANSI SCSI revision: 00
usb-storage: device scan complete
SCSI device sda: 2013184 512-byte hdwr sectors (1031 MB)
sda: Write Protect is off
sda: Mode Sense: 23 00 00 00
sda: assuming drive cache: write through
SCSI device sda: 2013184 512-byte hdwr sectors (1031 MB)
sda: Write Protect is off
sda: Mode Sense: 23 00 00 00
sda: assuming drive cache: write through
sda: [CUMANA/ADFS] sda1<5>sd 2:0:0:0: Attached scsi removable disk sda