Hey guys, I'm curious. Has anyone out there had any issues with M601 batts failing? I've gone through 4 of them in about a month and it's beginning to become disheartening. The customer service from Sean is fantastic at electronic-cigz.com, and I haven't had any issues with getting them replaced quickly, but it is getting a little frustrating. Sometimes the batteries last a couple of weeks, sometimes they only last a day or two. They're auto batteries and it seems the sensor that detects you drawing on the pv either completely stops working, or you have to draw on it so hard that you get a mouth full of e-liquid. Anyone else experienced this?