Think you just solved your Question when you put blank media in a drive it can change the name of the drive, just tried It In my Cd-RW it is now called cd drive E but unless the disk is full if should give you some idea as as to how much space is on the disk. I Have had DVD/RW disk that did the same (Fortunatly i got them given) just ended up throwing them away. you could always try burning on a anouther computer (Friends/Family Etc) and if they work on someone elses it will be a definate hardware problem on your computer, The next best thing is to use them as a place mat for your cups or glasses (sorry about the long reply)
I THINK YOU GUYS ARE RIGHT!!! the discs must be crap... i guess i could color them & give everyone a set of cup coasters for Christmas hahahaha...