USB was created using unetbootin
Had the same problem last night when creating a Live USB or a
full USB install on a flash drive.
1) Completely delete the flash drive thru PCC disk management program
and recreate and reformat that as well. Better than GParted.
2) check with the testdisk program that all parameters are correct
3) if not reboot and go back to step 1
4) then redo the install with unetbootin or the PCL Live USB Creator (preferably)
The above solves 99.9% of my problems on my machine.
If not post back then.
Something from a previous install is hanging around your MBR or partition table
stopping the process from successfully completing. Otherwise I need over 1.5ghz
processor to burn a CD with the newer disk burning hardware. So I use
flash drives instead.
I've done this so many times I have it memorized.
Have a good one.