I have the same problem you have , see mine in another post.
It seems to me that everyone of us has its own experience good or bad in burning dvd be +r or -r. There is not any rules to follow, to reach a certain result , and we all loose time and money for this.At the end I thing it is better to buy the original one saving time and money.
Then no one say if there are the same problems with Cd's but only with dvd and this is the reson I have postponed the os sw' update , having experienced bad results with trouble.
Probably also the Dvd drive must be investigated. Has anyone some spec of this mk4?( I have it on e46)
Appreciate your comments.
Mario