I've just purchased a Sony RDR-HX900 HDD DVD Recorder last week. I've started to transfer movies from my camcorder to the recorder. I've successfully transferred some movies to DVD+RW, but when I try to burn on to DVD-R, it burns correctly, but when I place the disc in to my pc, it shows up as a blank dvd I do not think there is a problem with the DVD-R discs, as I have used them to transfer movies from my PC to DVD. Can anyone suggest what the problem may be ? Thanks in advance.