Cat doing # 2 in the wrong place!!!!

My dad just brought me up my cat that I grew up with. His name is Cry Baby and he is 3 1/2 years old, he has been at my house since last Monday (so taday a week and one day) he was house broke at my house back home and when he came up here he was doing fine and than the last few days he has been pooping in the den. He pees in the liter box fine and he will poop in the liter box fine but he will not stop pooping down in the den. He goes in the same corner and it looks as if he is doing it at night becuase it is always there in the morning and it is not their when we go to bed. Please help this is gross! He is such a good cat, I am not sure why he is doing this all of the sudden. :confused:

I have to ask this...And it might sound stupid,so bare with me.... :D

Your dad brought you the cat you grew up with.And this cat is only 3 1/2 years old?

Not, grew up like all my life. Sorry, we grew up with the momma cat her name is Sassy. She had kittens, and we got rid of all the other kittens except this one becuase he was so cute. So we took him to the vet got him fixed and his mom and all his shots and dad said we could keep him. He than brought him to me the other day. I am sorry my bad. I guess that did sound a little dumb oh yeah I am only three years old. I was not thinking sorry! :o