Samsung SH-S183A wont burn at 8x with 8x media

I have just got this new drive as i have 680i mb and doesnt had many ide slots.
Well the Pioneer 111 i have burns the 8x media at 8x the Samsung only at 4x.
I have quad core 2 gb of ddr2 ram loads of power firmware updated .
Anybody got a clue whats happening?

What media are you using ? Maybe the Samsung does not like them, try some MCC or TY ones