CompuServe Messages

We are having a serious problem here that I would appreciate your advice on. As many of you do CD-Rom burning I was hoping that somebody might be able to help. About 8% of the CD-R disks that we burn are turning out to be unreliably read. This is a very high percentage. The disks give every indication that they are burning correctly. That is, we see no errors. We then take the disks and put them into another computer. That computer reads in every file and verifies that all of the data can be read. ("Verifies") The problem that we are having is that the verifies fail. We then put the disk into a different verification computer (we have four of them running) and in about 50% of the cases the verification then passes. What are the most likely causes of this problem? Is the CD-ROM drive not calibrating? Is the CD-ROM drive making errors? Is the media bad? We are following all of the rules, so I am certain that the problem is not the obvious stuff. IE, we are burning 4X media on a 2X drive, so the media IS properly matched, etc. I am hoping that you know whether drives tend to be bad/unreliable or if the media tends to be the common problem in cases such as this. Thank you for any help and assistance that you can offer. —– The CD-R drive we are using is a "Plasmon 4101" and the media is Verbatim 4X. We are recording at 2X speed.