From the froyostone thread: (for the rootfs problem when you can't get back in to android the second time)
Delete the Android folder. With the system files directly on the root of the card, if an Android folder is present, the boot-up will try to find rootfs inside it and will stop booting because it can't find it. Without the Android folder, the boot-up will look directly at the root of the card and find all it needs to boot.
You'll need to delete the folder each time you boot back into Android because Google Maps creates it for its data files. But it is safe to delete it."
Worked great for me! I'm back in Android baby
