You are using bunk discs...I would suggest some nice Verbatims or Taiyo Yudens.
You are trying to put to much onto the disc...reduce your target size to 4400.
Ease up on the multitasking too...
@teddy
I've been fortunate to have my NEC and BenQ for around 3 years with around 1000 burns each on them and they are still going strong. I know a lot of Litey owners who have had their drives for a long time and are still using them as well...could be you just got a bad drive.
@vegas
Post a log please.
I think you need to go back to the drawing board...corny and mmalves have given you your answer and I think I did too in another thread.
Google is your friend.
How old is the drive...how many good burns have you got out of it? Nothing lasts forever.... if you were happy with the drive up to now and have had a good time with it in the past don't hesitate to get another one.