I received a new M401 (my first) yesterday, and it just finished its initial charge. I left it in for 12 hours. The thing doesn't seem to light consistently. When I drag, the light goes out quickly, after about 2-3 seconds. It doesn't blink, mind you, like it's supposed to do after 5 seconds. It just sort of fades out, and I can't get a decent hit off it. And I can't even get it to do that consistently. Sometimes it just doesn't work at all. I just started charging up the spare battery and am gonna see if the same things happens with that. Does anyone know what could be causing this? Is it a dud battery? PS. Even after 12 hours, the charger light stayed green the entire time and never turned red. This also happened with my pen-style RN4072 though on the initial charge, so I didn't think anything of it. Should I have left it charging til the light changed?