Rabbit litter training difficulty

Question
We adopted a 9 month old Dutch male bunny from the Humane Society.  He was not litter trained and did well learning in his small cage, but when let out would urinate in corners and leave pellets everywhere.  We tried putting other boxes in the room he had free run in, but he would urinate right beside them!  He is now in a 4x3 cage in another part of the house and at first used his litter box for urine all the time and the pellets most of the time.  He really came out of his shell when he got his new cage and is much more social and appears happier.  However, after a week or so, he started urinating all along one wall of the cage.  We finally have put litter boxes all along that wall of the cage to prevent constant clean up.  He is not neutered.  Is it too late to do that and hope it will improve his behavior?  Is he perhaps simply too old to learn the behavior?  When he is let out of his cage, he doesn't urinate anywhere in the room and rarely leaves pellets - which is a great improvement, but having all the litter boxes in the cage has limited his space.  We have been working with him for over a month now, and are kind of frustrated!  Thanks for any help you can give.  

Sheila (and Bandit)

Answer
hi sheila i,m not sure what to do but would like to say we in the uk do not have our rabbits in the house,all mine are in a very large shed and each rabbit has a individiual cage.having them indoors creates lots of problems as you have found out and i would not like to find it had urinated and left droppings in my house.
dave.