Problems with DVD-R backups

[Mr Slippy]

Yes and Yes!

I create a new DVD (ISO) and then dragged the directories AUDIO_TS & VIDEO_TS to the new compilation.

I created these files by ripping my original using Smart Ripper and then using DVD2ONE to compress the film to under 4.7Gb.

After speaking to someone today, they told me it could be Nero that it causing the problems when I am writing the disk. i use Nero 5.5.7.2. ANyone know any truth in this, also I choose to create a DVD (ISO) not a DVD (UDF), what is the difference?

Thanks