bluetooth : hcitool dev shows no device

Hello.

I need to activate Bluetooth on my laptop.

lsusb gives:

Bus 002 Device 005: ID 0b05:1712 ASUSTek Computer, Inc. BT-183 Bluetooth 2.0+EDR adapter

According to lsmod, the bluetooth and hci_usb modules are inserted, but when
I try

# hcitool scan

I get

Device is not available: No such device

and

# hcitool dev

gives nothing: just

Devices:

I see no errors in dmesg or /var/log/debug.

Any hint? Thanks!

--
Fabrice DELENTE