Another thought here.. My kitty was having litterbox confusion, and we put litterboxes in many spots. We were also advised by a vet that without a UTI or other physical problem, this is frequently a sign that the cat's world is too big, and should be made smaller. we accomplished this by closing the doors to all the rooms, except the main rooms (Lv/Dn/Kit) and the master bedroom, thereby making the world smaller for the cat. Eventually we were able to remove the litter boxes except for 2,and we no longer see messes or puddles on things (usually it was in the corners of the rooms). The vet's theory was that because her world was too big, the kitty would get confused and forget where the box was. Adding to this was her urgency because of her physical digestion problems.

One other thing, We switched from normal style cat litter to very fine "clumping" litter (like sand). The vet suggested that some cats are very fussy regarding toileting, and just don't like the feel of the regular litter on their paws.

Just a thought.