If your cat is not using it's litter-box and leaving gifts in all the wrong places my suggestion is you check the following...1. Does your cat have easy access to the litter-box? Sometimes if there is too much traffic around the area where the box is kept the cat will not use it. They do like their privacy, you know.
2. Is the litter-box big enough for your cat? They like to be able to move around in the box and scratch while they turn their body.
3. Have you recently changed the type of litter you use? Many of the litters have added chemicals to reduce odour but the cat is very affected by the very un-natural scent.
4. How many cats are using the box? You should have a box for every 2 cats.
5. IS THE LITTER BOX KEPT CLEAN? This is very important. Cats are clean animals and they do not like a dirty litter-box. Stay on top of it and you should not have any problems.