Your experience fits the description of a "flooded carto". This can be caused by a couple of things.
Too strong of a draw while vaping a cartotank can cause
too much e-liquid to fill the carto. The liquid barrier can't handle all of the juice and some leaks into the center air hole and can get sucked up when you inhale. Advice: Slow down. Take slow, deliberate, gentle draws of 3 - 6 seconds length. Imagine sucking a thick milkshake with a straw.
Filling or refilling a cartotank with the top cap off is poor technique. When the top cap is replaced, the sudden increased pressure inside the tank forces juice into the carto leading to flooding. Refill your tank with the method shown in the video of this cartotank tutorial:
http://www.e-cigarette-forum.com/forum/blogs/baditude/3710-5-cartomizer-tank-setup.html
You
might be able to save a flooded carto with this method. Remove the cartotank from your battery device. Turn the tank upside down so the drip tip is facing the floor. With a paper towel on the other side to catch juice, blow forcefully through the drip tip. (You don't want to encourage more juice to enter the carto while blowing, hence blowing the tank upside down places the carto's holes in the air space inside the tank.)
Next, put the tank back on your battery device. Do a couple of
short dry burns (firing the battery without vaping). The idea here is to vaporize some of the remaining excess juice in the carto.
Don't over do this part, or you run the risk of burning the filler material and ruin the cartomizer.
Hopefully this helps.