yup, its possible for a flash drive to crash and just give gay errors, i had this happen to a few of mines. its a big possibility that the thing is busted or it may jus have permission issues cuz u said u cant access it. did u install a new OS recently, i heard that some usb drives encrypts data as soon as it is stored to prevent abuse but that the really new kinds
so if u installed a new OS, the drive thinks thats it a new pc and will not allow access...kool huh