what is the difference between DVD-R DL and DVD+R DL ? need help

[The Notorious]

i have bought some DVD-R DL and i can't seem to be able to burn on them any movie, everytime i try dvd decryptor or imgburn give me an error about layer positionning. i use a NEC 3550a with firmware 1.05... i see must of you guys use DVD+R DL

[The Notorious]

i have tried this procedure with no luck

Instructions Rip w/ DVDDecrypter and AnyDVD- Burn w/ Imgburn:

1.In DVDDecrypter go to Tools> setings>General> untick Check for Structure protection

2.Now go to I/O and tick ELBYCDIO-Elaborate Bytes

3.Enable AnyDVD

4.Now insert Movie( foxes head turns red) and go to Mode in DVDD>Iso read> click the decrypt button. It will create 2 files- image and a .mds file

5.After ripping turn AnyDVD off ( right click taskbar foxes head and click on exit)

6.Open ImgBurn> Tools> Drive> Change Book Type>DVD-ROM

7. Now go to Mode> write> find the .mds file you created and click on it and the hit the write button

i'm quite sure if i really did changed the booktype since in the list i only see DVD+R DL and no DVD-R DL

[GKar]

It depends on the drive you have, in your case stick with +R for all disks. It goes back to when the DVD Forum was at war with the DVD Alliance over which standard should prevail and they tended to build their drives to favor their own standards. I could be blowing smoke out my patoot though. I have found with my NEC 3540 it prefers Verbatim MCC003 +R (8X) and MCC004 +R (16X) and it more than likely applies to their +R-DL disks as well.

[The Notorious]

ok i will go buy some +R tonight.....

but when try to change book type it leave it to dvd-r dl how i do it is i go to

tools --> drive --> change booktype --> select nec ---> choose dvd+r dl (no dvd-r dl in the list) in the new setting i pick dvd-rom

it says it has been changed but it's still show dvd-r dl

[GKar]

You can dig around here for some more info on your drive:

http://club.cdfreaks.com/forumdisplay.php?s=a44e07958b0c5715d3ae820b09ce7a9f&f=86

Liggy and Dee make some custom firmware for NEC drives:

http://liggydee.cdfreaks.com/page/

Buy good quality media and your experiences will be better:

http://www.digitalfaq.com/media/dvdmedia.htm

Try Taiyo Yudens or Verbatims