Sometimes after a re-wick mine does a little. Basically its the airflow section that gets flooded with juice.
Experience and several rewicks later Ive come to the conclusion its because Ive not used enough cotton and/or ive left too much space between the juice holes and cotton on the RTA.
Its a fine line between spitting and leaking!
Strangely the problem seems to fix itself if I leave it sitting overnight or unscrew the RTA top and poke/move/remove some of the cotton wick inside.
The thickness of the juice has an affect on this too.
I use multiple tanks, because I don't always have time to refill the tank I'm using.
I make every effort on my part, to insure that the juice doesn't leak. I store them upside down, vents closed, and wrap then in a napkin until I'm ready to use them. I'm typically driving between customers and store them in the console.
The wick stays wet, it never really goes dry using this method. And you've completely cut off any way the tank can leak.
The only tank that I allow to remain upright, is the one I'm currently using.