just to add a bit more smoke, I've found that the SATA BIOS options to use SME may be quite different that those for WINDOWS!
a recent machine with 2 sata drives refused to install XP except when using the board RAID option, SME would only use the non-raid!
Also some of the IDE/SATA combinations ( Primary + SATA, SATA+secondary, etc ) gave grief, but in the end, all worked with SME software mirroring.