try to fix your usb if problem usb. with gparted in bt. or search for GParted LiveCD, remove all partitions on USB if any, create new partition table and partition. im not sure but i do think debian/ubuntu based distros doesnt support fat32 so install dosfstools for fat32 support in backtrack. i dont know if gparted livecd has support, so google it.
hope this helps.



