Nero Speed Mesurement

iT’S NORMAL THAT IN THIS TEST BEFORE TO BURN THE DVD-R NERO SAY THAT SPEED IS 3x???

I WRITE…LOOK WITHOUT PROBLEM…AT 4x!

ANOTHER QUESTION…WITH 0047 FIRMWARE I CAN’T WRITE DVD-RW AT 2x,BUT ONLY AT 4x…WHY???

THANKS!!