Formatting my flash Voyager

Hi My name is Duncan and i have a question :) I have a memory stick, a corsair flash voyager usb 2.0 256mb. i have had it a while now and i kept some music on it and some pics and i played it through my cigarette lighter in the car. Everything was working ok till one day i plugged it into my computer and now it keeps saying it needs foramtting and it wont play anymore, I cannot access any of the files and i ttried to format it using the disk utillity that came with it but it just says formatting failed...can you help me sort this thanks