House training question

by Colleen
(Mesa AZ)

I have a 3 year old J.R. that I adopted about 2 years ago. I am having difficuly house training him. He is well behaved, and doesn't go potty in house when I am home, and I usually have him in a cage when I am not home. The few times that I have forgotten to lock the cage, I have come home to piles of poop,and have to look for places he may have peed. I would love to let him run free when I am not home but I just don't trust him. I have never had a problem training a dog, but this guy is just not getting it. I ALWAYS take him out before I leave, and on rare occassions, he has pooped in his cage. I would appreciate any help on this.This has been going on since I got him.