Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Problems with recorded disks

It plays commercial DVDs properly but it is often incapable of playing or recognizing those it has burned itself. I just tried to record two programs and got "disk error" as soon as I pressed the stop button. In other cases, I have gotten "unknown data" or "empty disk" for freshly-recorded DVDs.Cleaning the disks helps in a minority of the cases. I have probably wasted twenty or more recordable DVDs (and I have no idea of how many finalized ones are actually playable). The directions (page 8) warn against trying to clean the DVD player's lens because the optical unit is more delicate than those in read-only DVDs.