I had this same problem when I was creating a schedule, I think when you have a lot of group races in you schedule you sometimes get this, maybe if you weed your schedule a wee bit from big races allow some other races that come with the game like listed, maidens, and so on, this problem might not happen, worked for me I don't know could work for you atiggerx

wow... that is odd, has to be a glitch then atiggerx, you should tell mark or send him the save files or something mate.