Cd-rw and dvd+rw Memorex wont burn. Why?

I got some Memorex cd-rw and some dvd+rws. i putred them in my dvd+/- drive and did the drag and drop to the d: drive (.rm files). I clicked write these files to cd and it started, after like 10 to 25 min. it just pop up a window saying that the dvd+rw or the cd-rw is render useless or is no longer burnable. When i use them for clonecd (cd-rw) it worked great for a audio cd. I even try using nero to burn the .rm but no use. Can anyone tell me how i can solve this problem. please help!!! :bow: :bow: