I have had the same problem with any bot I try running. Mind, I usually run 2-3 bots at a time, 2 of them usually being kMiner. Whenever I come back from school or wake up in morning, (usually 6-10 hour periods), at least two of my bots are dead or all three are logged out and dead. I run them all on signed, and my internet connection is stellar. I don't even know why this happens.