I bought a DBW a while ago, and I've only encountered one problem. When I use it for a while, it starts to not work. If I put it all the way down, it just doesn't do anything. It only works when at certain positions. If I move it up and down a bit, it works again, but only for a few seconds. I have the power adaptor for it, so I have no idea what's goin on...please help!