You were told to use 2.5.0.0 because it isn't the problem, and you didn't.
You were told to burn at 4x or 6x because your burner might do a better job at those speeds (those blanks are rated 8x after all), and you didn't.
You were told to enable Verify because that's what ensures the disc was correctly burned, and you didn't.
If you're not going to try our suggestions then stop wasting our time.