Kaddressbook

Hi: Does anyone know where the config file is for kaddressbook in Kmail? On my home machine my address book opens fine but if I try to save it says that another application is accessing it and it refuses to save. I had some mail problems related to my MTA and had opened Sylpheed and Evolution to try to salvage my mail so perhaps it is related to these as it was fine until this point..how many times have I said that.... Paul