Have you power cycled the Vox a few times, or have you just been recharging it without turning it off? I would definitely turn it off if you haven't.
Then I would try to do a hard reset. To do so, hold down the power button for at least 10 seconds. Here's a link to that tip, and to a few more troubleshooting tips:
http://goodereader.com/blog/electron...some-problems/
If nothing else works, I would exchange it.