I am assuming that this is "fake RAID", rather than real hardware RAID, because you can see both disks (if it were real hardware RAID, you would only see one disk, the pair that give you the RAID1 mirror structure would not be visible, but would be hidden behind the RAID controller).
You said you had RAID1 operational, and it's clear to see that this is the case for Windoze, because you have two identical Windoze partitions, one on each disk, constituting the two mirrored disks of a RAID1 pair. However, you have dissimilar partitions on the disks for your Linux installation, so the other installation is NOT RAID.
Sorry to say, I think your installation has gone wrong around the disk partitioning stage, because the partitioner has placed different partitions on different disks, when what you should see is two identical RAID partitions...thats the whole principle of RAID1, if one disk barfs, the other one keeps on until you replace the bad disk, and the pair are resynched.
Restart the installation, and when you get to the disk partition, create two RAID partitions first, then merge them as one RAID1 device (probably something like /dev/md0, but the partitioner will guide you and do all that) then once you have a situation where the partitioner tells you you have a RAID1 /dev/md0, then go on with the install as if it were one disk.
As an afterthought, you may have done all this right, and still have the problem. I have, in the past, come across one or two entry-level Intel Server Mobos where I have had exactly the same problem, and despite doing what works elsewhere, I have not been able to get it to work. However, I don't think that is the case here, because Windoze is clearly working OK on the RAID1. All that notwithstanding, you might like to try Fedora Core 6, I have found that to be a bit better at RAID than some disros...