Why does my USB mass storage device not work after resuming from a Windows XP sleep?
I deal with problem every day, I’m from Memorex Tech. support so I recibe phone calls like this every day, what you could do is first check your service pack, then you can go to the device manager and go to the universal serial bus controllers and then click on the yellow label and check for changes in the device, and also you can try to update the driver, or just asigne another drive letter.