So glad I am not the only one with this problem. Molly is still very young and new to the house breaking thing, but she does the same thing. Outside is just too interesting to poop. She pees just fine within a few seconds of going out but it is like the planets have to allign correctly for her to want to poop. Of course inside isn't as distracting so no problems going inside. Our solution is to constantly monitor her, which isn't hard because we live in an apartment and block off access to rooms other than the kitchen and living room. She can go in other rooms when she proves she won't go in the house.