Mobo/cdrw... help?

Ok… need some help…I’m running a 1Ghz Athlon on an Abit KT7-RAID mobo, 512r, 2x120g hd, liteon 48246S(overclocked to 52246S), WinXP… More info on the mobo, it has 2 IDE slots for Ata/66 or older, and 2 slots for Ata/100 or RAID built in on the mobo controlled by a Highpoint chip on the mobo(not an add-on card)…

The liteon is new, I installed it and works fine generally. I put it to NeroSpeed Test though, and the read speed came out at a low 20x! At this time, the drive was plugged into the Ata/66 slot. I checked Device Manager, and realized the drive was running on Multiword DMA Mode 2 instead of Ata/33 or UDMA33. Therefore, I decided to plug it into the ata/100 slot instead, it was fine once again, fired up NeroSpeed, and got a 17x. And yes I have tried different sized discs that were tested with SmartBurn to be 52x capable, I also tried original(non-cdr discs), all the same.

I have also tried deleting the IDE driver in Device manager, same results. Btw, when my drive is plugged into ata/100, the IDE controller is not even used, instead, it is connected to the Highpoint ATA100/RAID Controller, just like my HDs.

Can someone tell me what’s wrong?
How can i set it to ata33? And if this really would fix my problem?