Ok, tested with the 2.6.32-trunk-686 kernel from Debian testing and the result is the same. This is the log from dmesg | tail
[ 4698.652329] cdc_acm: v0.26:USB Abstract Control Model driver for USB modems and ISDN adapters [ 4703.488138] usb 4-1: USB disconnect, address 2 [ 4704.720161] usb 4-1: new full speed USB device using uhci_hcd and address 3 [ 4704.891025] usb 4-1: New USB device found, idVendor=04e8, idProduct=5a0f [ 4704.891030] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 4704.891033] usb 4-1: Product: SGH-L760V [ 4704.891036] usb 4-1: Manufacturer: SAMSUNG MTP Device [ 4704.891038] usb 4-1: SerialNumber: A353666023139976 [ 4704.891168] usb 4-1: configuration #1 chosen from 1 choice [ 4747.632226] usb 4-1: USB disconnect, address 3 As you see, the phone is correctly detected as a GSM Modem at first; the 4703.488138 entry shows when I choose the "USB device" option at the phone itself... it disconnects itself and attempt to reconnect now as massive storage device, failing to be mounted. Thanks for your attention, Eugenio