I'm having trouble with my brand new Quantum D2. Since I got it a couple weeks ago it's been misbehaving. When I twist on to activate sometimes it doesn't come on at all, sometimes it comes on dim, and rarely it comes on full brightness. I'd say it only works correctly about 10% of the time. Battery if of course fully charged. I sent a note to illuminationsupply but haven't heard back yet and thought I'd ask here. Any suggestions?