We crate trained Cosmo too and had the same problems! How funny! The good news..he is now 11 months and accident free! Like you he got going potty easy but then would come in and poo. My mom said maybe we were not giving him enough time...which was a good point. I started to make him stay out longer even after he would pee and come back to the door, I would tell him go potty and within minutes he would leave the door and go poop. We have sliding glass doors which we now have bells on, he nodges the bells when he needs to go outside. We have kittys or we would get the outside doggie doors. I was frustrated at the same time you are, hang in there it will take!
