I had a few CDRW's written with Windows explorer using Pioneer DVD writer. Now I am using a CD writer and Nero 6, but I am not able to write anything more on to those CD's even though it shows that they are empty. I was able to erase them, but the Nero writes everything, but when i verify the date, it says "Data verification failed" and it shows nothing in the explorer. Please tell me what could be the problem. Thank u.