This is Toast 7.1.last: I have created a MusicDVD that works well on my set-top box, on my sons' WinXP machines, but won't mount on my Mac, the machine and drive on which I made the disk. Instead I receive the following error message: "The disk you inserted was not readable by this computer." I have an external, firewire attached drive and an internal DVD reader. This error comes up if the DVD is +RW or -R. Both those types of disks work on the other equipment.

As I understand the Toast Help system, these disks are supposed to be playable on Macintoshes as well as set-top boxes. What gives?

Thanks for your help. ...edN

So the error appears regardless of using the internal or external drive or using +R or -R media. My best guess is you have an OS problem that is affecting the ability to mount burned video DVD media. Run DiskWarrior if you have it. Is it only the music DVDs that won't mount or is it also video DVDs that you've burned. How about commercial video DVDs?

Thanks. To answer your questions:
* same error on both internal and external drives, yes
* same error on DVD-R or DVD+RW -- haven't tried any other format
* don't have any home made video, sorry
* will receive this error if I try to mound DVD-RAM disks created on a Windows PC (but I think I understand why.)
* commercial movies do not mount either (and I only have ones I've purchased) -- I play these with VLC which is able to see the disk

My questions:
* I've seen DiskWarrior mentioned numerous times. Pardon my ignorance, but how might this utility help me?
* Is there possibly something about the file system or disk layout created by Toast that is Windows only, or at least not Mac enough? I ask because when I look at the Info pane in Disk Utility, it's seeing a DOS FAT-16 file system.

Thanks for the quick turn around. ...edN

Yours ask good questions. DiskWarrior fixes errors in the system directory that is more than what the First Aid in Disk Utility can fix. I've had situations where DiskWarrior saved the day for me. The alternative would have been to do an entire new OS install. I consider it a must-have utility for all Mac users (and I have no self interest in that statement). I don't know if it will help in this case.

What might help is a laser-cleaning disc. Maybe there is some dust on the drive's DVD read laser.

I'm pretty sure you problem is with the drive or the OS and is not an issue with the discs themselves. As you seem to be aware, there's a good possibility your drive doesn't support reading DVD-RAM discs or those discs were burned using packet writing on a PC. Macs don't read packet writing (where the disc is used similar to a hard drive where files can be added and deleted).

Years ago I bought a new G4 iBook and it wouldn't burn any discs with either the internal or external drive, although it could read them. Since it was new I did a complete reinstall of the OS and the drive worked perfectly afterward. Something was wrong with the factory OS install. So I know the OS can be corrupted in a way that affects optical drives.

* I'll definitely take a look at DiskWarrior; thanks!
* I'm a little leery of those cleaning disks -- have to think about it.
* DVD-RAM is possible and successful with my external drive; the issue seems to be file system based because I can format a DVD RAM on either PC or Mac, but cannot exchange them, one for the other once formatted -- even if I choose FAT-32 on the Mac side in Disk Utility. Perhaps this has something to do with packets. This in contrast to magnetic storage which, under FAT-32, is pretty good cross platform on portable USB/Firewire drives. There is some public domain software (whose name I can't remember right now) that installs on Mac and opens things up further for alternative file systems to be mounted; I have not experimented with that although it is spoken of highly.

Thanks again for your help. ...edN