Burns with Liteon LH-20A1H

I recently purchased an LH-20A1H and some Verbatim 16x media. My 1st burn was successful at 16x speed, But after that, It hasnt burned at that speed.

My last 2 burns started out going up to 11x-13x speed, Then dropping drastically down to 8.3x.

I do believe that I have a 80pin ide cable connected and the burner is the only device connected to that cable (No hds or anything).

The cable is a Thermaltake A2053 ATA 133/100/66 round cable.

Speed Selected: 16x
Speed Start: 6.62x
Speed Average: 9.30x
Speed End: 8.04x
Speed Max: 16.56x

My firmware is LL0A

Media ID is: MCC 03RG20

Current hds have all been recently defragmented as well.

Should I get an updated firmware, Or what could be causing this drastic decrease in write speeds?