Problems with my DC

Everytime I burn a game onto a CD-R and put it in my DC to play it keeps saying Please Insert Game Disc. The game may work fine the first couple of times but it will keep reseting in the middle of play. My Dreamcast was manufactured in March of 2000 if that will help any. Backups i have played are Crazy Taxi 2 and Stunt GP. But they have ####ted reseting in the middle of gameplay also. And now my DC wont recognize the Utopia Bootdisc like it did when i first ####ted using it. Does anyone have any thoughts on this?