Your Jim surely doesn't feel well in his current situation...when a new cat moved into the neighborhood Nellie started spraying, too...but fortunately only outside in the garden...just to make sure to the other cat knows, who's in charge!!!

I guess Jim is a little stressed by those other cats and if they once start this spraying thing you'll have to do a lot of cleaning...the only advice I can give you is to try to think the way Jim does and to rule out his problem...maybe a serious animal communicator can help you here...I've onced tried it with a Canadian Animal Communicator and it was very fascinating what I learned about Nellie...I can truly admit that our relation is even closer than ever!!!

Maybe even a good cat behaviour book will help as well!

Hope you'll solve the problem soon!!!