[quote=Corrywe had no female cats in the house but he walked up and wiggled his tail and sprayed all over my daughters nintendo machine! [/quote]
I've had a lot of cats. Even if they are neutered, they sometimes will spray. I think they do it if there are other MALE cats in the house because that is how they mark their territory. Our previous cat family had two males and one female. One of them was a "barn cat" at birth, and he was the most vile cat I've ever had. He sprayed constantly, despite being neutered. I've always believed it was because of our other male. He was definitely top dog, uh, cat, and he sprayed just to let the other male know it.
The cat family we have now consists of one male and two females (one now). He too is neutered. I've seen him spray outside, especially when our neighbor's cat hangs around. He goes around spraying on everything. I wonder how he has enough capacity for the amount he does. But he never sprays in the house.
I'm not expert, but this has always been my experience.