I'm using a Liteon DVD Recorder and TDK+RW disks but am having a problem with erasing and re-recording. So far 7 disks that once worked fine, all of a sudden become unreadable, uneraceable and cannot be recorded over. I've tried using the laptop's DVD program to erase them but it won't read those disks either. They have somehow become contaminated for no reason I can detect. I tried cleaning but that did nothing. Can anybody help, this thing is eating my disks as fast as I can buy new ones?