OK, I am a relative DVD n00b.
So far I have found that with my 812s ('J' official firmware) that my kprobe 2 results for 4x -R are dodgy. I am using Zero Defex (Ritek) media.
However, using Zero Defex (Ritek) 8x +R the kprobe 2 results are excellent.
Why is this? Also what is the difference between -R and +R media?