since your last cat peed in the house, your new kitty could also just be smelling that and covering it up with his own smell.
my parents' cat has frequent urinary tract infections, and she pees all over the house. she is also very territorial, and doesn't take kindly to male cats in particular. i got a male kitten, and once he grew up a bit he started spraying where she had peed. he was neutered asap, but he still continued to mark certain areas of the house. my parents wouldn't tolerate it, and they had him euthanized. :roll: poor guy, it wasn't his fault!
their female cat continues to pee all over the house, yet she rarely gets scolded seeing as its a health problem. i had to move back in with them for a while, and i brought my 3 cats with me. i have 2 boys. their cat tolerates my oldest, but she really has something against my other boy. she attacked him constantly, or just hissed and growled if he went in the same room as her.
he has never sprayed in any of my apartments, but after a while...he was so stressed and so angry at her, he started spraying where she peed. since my parents don't have the sense to try and get rid of the cat urine, i bought a bottle of febreze. when i'd catch a cat peeing on the carpet, i'd say NO and carry them to the litter box. then i'd thoroughly clean up the urine and soak the carpet with febreze. if i caught them sniffing the area, i'd chase them off and soak the area with febreze again. i managed to cut down the areas they'd pee in, but my parents' cat just refused to stop peeing in several places. my poor boy was yelled at or smacked just for sniffing these areas, i was at my wit's end! luckily i moved out and don't have to deal with that anymore. i was terrified that they'd have him euthanized while i was sleeping like they did to my last boy...
i'd suggest getting yourself a bottle of scented febreze and soaking down every spot your cat has been peeing on to get rid of the odors. getting him neutered should take care of it, but if it doesn't nix the problem entirely...keep that febreze handy! if he smells urine somewhere, he'll think its ok to pee there. gotta get rid of the smell!