I have a 500GB Formac external harddrive which is 2x250GB in one enclosure. I've been using Disk utility to raid it into one disk. Someone told me that it's meant to have hardware raiding so the software is unecessary. but since I bought it, it's always showed up as 2x250. I also have a La Cie of the same type which on the other hand only shows up as one disk. is there something wrong with the formac?