Format of the server rules was not recognized

Hello, All was fine until installed office 2003, now suddenly i am getting this error message “THERE WAS AN ERROR READING THE RULES FROM THE SERVER. THE FORMAT OF THE SERVER RULES WAS NOT RECOGNIZED”. i am running windows xp with xp sp2 and the server is windows 2000 server with service pack 3 and exchange 5.5

Also, my out of office assistant does not work either.