There is a simple explanation - the HPT366 controller isn't a RAID controller. It's a normal ATA controller. Maybe this "friend", as you call him, told you it did RAID?
If you want to go RAID on the BP6, you'll need to buy a PCI RAID card.
Myself and several others recommend ignoring the HPT controller altogether. It has been known to completely destroy hard disks. However, some have had no problem with it. But I don't trust it with my valuable data.
I use a Promise Ultra TX2 ATA/100 card (non-RAID) for my disk subsystem, in PCI slot 3 where it shares an IRQ with the redundant HPT. Promise also make RAID cards, and I can thoroughly recommend them.