DVD-R vs DVD+R DL disks

[davidlv]

Does anyone know the difference between DVD - & + R DL disks? I have just created 2 perfect coasters (write errors ) using Toast to copy my Snow Leopard Install DVD (Dual Layer) using DVD+R disks. I did the copy at 4X (disks rated up to 8X) on my MacBook Pro which says it supports DVD+R DL, and the DVD-R DL disks are really hard to find. Haven't tried using Disk Utility yet, may or may not work with the toast image file I have.
Is the original SL disk a DVD-R DL and is that the problem? Any advice appreciated.

 

[larkost]

They were two competing technologies vying for the recordable DVD market. The market finally decided that it could not decide and so all the DVD writers you are likely to find now support both. You should not really notice a difference in most cases nowadays.

My bigger suspect would be that your DVD drive is dirty and/or malfunctioning.

 

[davidlv]

Well, tried again using Disk Utility and it worked! I had to convert the Toast image to a DU cdr file (CD Master) image, and then use the Burn function. It took forever, but completed with no errors. Haven't tested the resulting copy yet. Maybe Toast was trying to write too fast?
Anyway, I have a copy now, so I can put the original away to keep it safe.