You're not alone. I heard that one of the Windows updates messed up the "policy" settings on some people's computers. At least, it sure seems coincidental that so many drives quit reading data so suddenly. I'm fairly certain this troubleshooting page will help you solve your problem:
Of course, you might just have a dirty drive. They do get goobered up after a while -- maybe you'll have to buy one of those CD cleaning kits -- the ones with brushes on the bottom of a disk? You could always just clean it carefully with a Q-tip too (be very, very careful not to scratch the optical reader though).