Just a quick qusetion to all u dvd guru's.

If I look on a BLANK dvd-r there is a small area which looks like a track(similar) which is a different colour than the rest.(looks unburned)
When the dvd-r has been burned then this area has vanished.

I was wondering whether this is the area used to lead out OR close off the disc. OR indeed what?

Reason I am asking is sometimes nero removes this area and when it DOESN'T it causes playback issues.
Other burning software removes it every time and no playback issues.!

The discs are EPERFORMANCE 120min 4.7GB.