That's odd, I've never had ANY 510 leak between atty and batty... It's always between atty and cart. The 'new-style' leak far more readily there than the 'old-style', presumably because the tube wall of the atty is a poor fit to the standard 510 cartridge diameter. But I get leaks there on all of mine, old and new, just more common with the new.
Since the atty wick/bridge protrudes farther into the cart, I always make sure that the cart is not quite as full if going on the 'new-style' atty, so that when the wick presses in against the filler in the cart it doesn't squeeze out several drops of fluid that then have nowhere to go but out... Seems to help a lot...
j