Check the format of the Drive, if it is NTFS (Windows) it will not be usable in linux. Also ...
From the command prompt type dmesg | tail -n 50 as soon as you plug the usb in.
This should tell you if it was seen and if an error occurred.
Next you can use fdisk (dangerous if not used correctly) to see what's the format.
There is also a command "modprobe usb-storage" but I haven't used this one....