I have just performed a clean install to 2 IDE hard drives, raid1.
md0 is /boot (auto), md1 is / (50 gb), and swap on both /dev/hda3 and /dev/hdb3.
The system fails the initial boot right when checking root filesystem.
I'm thinking this a kernel issue since boot log says md0 still mounted,
so it looks like md1 mouts ok, but md0 fails to mount.
I've has this happen on a working system after upgrading to 3.0.22
and I had to drop to shell and re-mount md0 with mdadm and init 3 to fix it.