I have an 8500 I've had for about 4 years. It has started doing a lot of "SELF CAL" and I have even seen "SERVICE REQUIRED" once. I am definitely going to send it in but I was just wondering what is going on with it. I checked the Rev. on it and it says REV 15. My wife's is the same REV but hers isn't giving all the error messages. When I send mine in should I go ahead and send hers in too ? Thanks for any input and nice site too.