RAID 1 Mirror broken, how to recover?

I have a GIGABYTE GA-MA78GM-S2H motherboard with a pair of Western Digital Caviar GP WD7500AACS drives that I had configured into a RAID 1 array. Just recently I noticed the AMD RAIDXpert message appearing that RAID 1 Logical Disk 1 is critical. In investigating via RAIDXpert (and through the RAID console at system bootup) I see now that instead of having two 750 GB drives configured in a RAID 1 array I have one drive configured into a JBOD array and the other configured into a RAID 1 array. It appears as if the JBOD array is acting as my C drive, the RAID 1 array is now appearing as Drive E (Drive D being my DVD burner).

How do I go back to configuring the two drives to be part of the same RAID 1 array without losing the data that's on the drive currently acting as a JBOD array? Both drives are fairly new (about 6 months old) and aren't showing any signs of other problems but I'd like to get my RAID array working ASAP.

Thanks for any help.