I've not seen this covered but thought I would add my 2 cents. After burning 100's of discs I'm firmly convinced that the easiest way to muck up a burn is to use blank media that isn't absolutely pristeen!
Usually, I'm extremely gentle with my pre-burned media and have not had too many problems. Most problems run throughout a particular stack of discs but as far as getting that errant bad burn? Only ones I've seen are on discs that I've scratched up or smudged. No way to get a good burn off of one of those.
Does anyone else think this to be true? If your blank media gets scratched up...forget about getting a good burn. It seems to make sense to me. That laser MUST be able to burn cleanly down to the ink layer or it's crap.
So, my advise...baby those discs until you get them burned. I think read strategies are MUCH more fault tolerant than write strategies.