I am working on training our new little Maltese puppy right now. I use an xpen to keep him in. He has a pad in there (i bought a pad holder to keep the pad in place and i love it). When i am able to sit right there with him i keep the door to his pen open and the minute he begins to start sniffing around i get him and put him back in the xpen and close the door. When he goes to his paper to potty, praise him like crazy! It takes a lot of time and a lot more patience!! Just keep at it....he will get it. The key is NO FREEDOM until totally trustworthy!! Good Luck!
Oliver and Brooklyn were trained the same way. I love the xpen method...it worked great for me!