You cannot have mdadm and dmraid co-exist, unless the mdadm partitions and the dmraid array are on separate drives. YOu can only have one or the other.
So if you have WIndows sitting on fakeraid/dmraid array, you install Ubuntu using the laternate CD, and when it asks for you to activate the SATA RAID array, you choose yes, and create partitions for filesystems as you would normally.
You cannot have mdadm and dmraid co-exist, unless the mdadm partitions and the dmraid array are on separate drives. YOu can only have one or the other.
So if you have WIndows sitting on fakeraid/dmraid array, you install Ubuntu using the laternate CD, and when it asks for you to activate the SATA RAID array, you choose yes, and create partitions for filesystems as you would normally.