I just got some new liquids and some 510 cartos (labeled 510D, Atomized Cartridges), and they make a LOT more noise than other cartos I have used. Is this normal? I am enjoying most of the flavors as well, but I loaded up a carto with some Vanilla bean and it tastes sorta burnt. I tried loading another carto, and same thing. I'm not sure if I did something wrong, or if that is just the flavor. Thanks for the quick shipping though, and so far Cappuccino Cream is a sure winner. 