Oh - oh! Didn't want to hear that! Mine had a software fault not long after purchase and had to go back to be 'fixed'.
My DRM-30 records quite happily on to various disks, currently Samsung Pleomax 8x, although as you probably know, branded disks are not always what they seem!
http://www.digitalfaq.com/media/index.htm
There are programs which will tell you if you have bought a stack of 'coasters', such as DVD Identifier.
