Dog pee marking inside house

Question
I'm looking for help for my new dog's behavior about pee marking inside of our home.(1st time small breed)
My dog's name is buster , he is a mixed breed between Lasa-apso and some farm mice hunting small breed (don't remember breedsname) , i got him on aug 2006 when he was around 2.5 weeks old, ever since he was a puppy we kept him inside the house with restricted areas since my wife and i work same times , I've put training pads 2-3 corners in room where he had access and always peed and excrements on pads but never anywhere in house , as soon as we come home we took him for a walk or atleast go outside with him in back yard(huge)Now since he turned 1 even i leave a pad never does hi's things on pads only goes there to eat any treat given to him , every morning when we wake up we take him out also before bed time ,but doesn't seem to affect him as during day when we're home caught him multiple times going to corners , walls , sofas, chair table.... and lifting his leg and letting few drops , when i catch him i tell him no pee, and take him outside, tried numerous times but he still does it , very annoying as when not noticed where peed smells badly inside . what would be the best way to train or change his marking behavior . i never had this problems with any of previously owned dogs larger breeds .

thank you for taking time to read my question and for any answer for it
Mike

Answer
You didn't answer my question. I guess that means he's not neutered. Well whatever. Just thought it was strange to think it would be ok to buy a dog that was far too young to be away from it's mother. Obviously you think it's all good. Unfair to rate when we hadn't finished the work really.