PC hardware: USB Storage problem

USB Storage problem

Hi, I have a problem with a flash drive.
Actually, it´s a digital music player, but I have used it as USB storage for a long time. If need, it's a Creative Muvo V200.
Anyway, I use it to carry my files around (I am in a computer network, so I do not have Admin rights), and it has always worked fine.
But recently, I restarted using it as Music Player, at first just with the few songs I had on it, but when I tried to connect it to the computer to put more in it, Windows wouldn't recognize it as a storage device. It just says 'unknown device', and I can't try with diskmanageer or Device manager or sométhing like that, cause I can't access them without Admin rights
Can anyone help me?
Thanks in advantage,
Faffnir