This is not my gun because I am not home, but this is one I googled and looks close to my problem. In fact this picture might be a little worse than mine.
There seems to be lots of mixed reasoning for Kimber's rusting. I read everything from low quality stainless steel to apparently they use some sort of sand blasting machine on both carbon steel and stainless steel. From what I read some people have luck with taking stainless steel wool and rubbing down the rust spots as they appear and eventually the problem goes away.