Look in your hardware browser under hard drives.
All of my usb drives show up there.
I got several of my usb hard drives to work by...
Open a Terminal then SU to ROOT
CD to MNT then MKDIR ( name of drive)....like (cruzer)?
Then GEDIT /etc/fstab
Then add a line to look like this:
/dev/sdc1 /mnt/backpack auto noauto,users,noatime,async
Depending what your hardware browser said your dev was ok?
make sure you save it!
I hope this helps