I have an atty/cartridge combo that will cause a leak as described when in the PCC. In my case, I took the atty apart to clean it, and when I put the wicking part of it back on there is a microscopic bit of it sticking out of the base, like I couldn't put the part back on all the way. I have a cartridge that is showing age, and the combination of the two does not make as good a seal on the tank, so when sitting in the PCC a bit will leak out between the cover and the battery.
You would think that is my issue, but trying 7 different tanks and 4 different attys, I would have to say no. I just can't see having 2 bad tanks/attys with the starter kit, and more bad tanks/attys in addition to that. I could be wrong.