This is a typical bad media problem. Changing to Ritek or Verbatim will usually solve this. You may try reducing the size of the disc in Shrink so it does not burn out to the edge of the disc:
Edit> Preferences> Change the Target size drop down menu to Custom and then reduce the size by 100-200 MB.
See if that works for you, You may have to reduce the size more.
You end up having more compression applied so the best solution is to change media. I prefer Ritek G-04. The stuff Im using now is the Ridata branded media.
I'll give it a try with other media, allthough I think Ritek is not that common in the shops here...
I have come across Verbatim, what about other brands like Fuji or Sony? I can get those easily, but are they more expensive than Ritek or Verbatim?