Bug#551286: Solution - probed
The problem is that some update between the installation of
linux-image-2.6.30-1-amd64 and linux-image-2.6.30-2-amd64 uninstalls
You just install mdadm and regenerate the initrd:
update-initramfs -u -k 2.6.30-2-amd64
Is not needed configure update-initramfs to load the modules, addind
mdadm it adds the binary mdadm self and all raid modules to initrd.
If update-initramfs rely on so mdadm is installed in raid based
system, then this bugs should be redirected to it, because dmraid is
enough to boot a raid based system.