It may be related to how you are formatting it but it also may just be broken.
Are you formatting it from a Windows computer? If so, are you doing a Quick Format instead of a full format? If you are in Windows check out the partitions on the flash drive in the Disk Management window.
If you are doing it in Linux, look at the flash drive with GParted to see if there are hidden partitions that need to be removed.
You could also try using unetbootin http://unetbootin.sourceforge.net/
if you only are looking to use one OS on the flash drive instead of multi-booting more than one OS.
Edited by James Litten, 21 December 2012 - 11:09 AM.