PS2 DVD Backup Problems

[evil_pikatchu]

I got some Problems with doing a copy of my backups on DVD+R.
90% of copies i do just stop burning at about 98-99% of the burning process, telling me that there is a read error.
I Actually got the Nec1300A DVD Writer and the Philips225RW only +).
Al my backups I did with the philips from orignal Game DVD, no problem. But when I try to copy the backups most DVD's fail.
I used Nero 6, Alcohol 120%, same result, always at the end of the burning process. I also used different media types, +and-, same result.
So what's wrong ???
by the way, both drives function with CD-urning