Comment 55 for bug 97655

dmraid and mdadm raid are two completely different modules that are AFAIK completely unrelated. dmraid is for hardware fakeraid while mdadm raid is pure software raid.

I've had similar mdadm raid issues though. I fixed it by running:
sudo dpkg-reconfigure mdadm

Accept the defaults and at the end it should show you that it is writing to a boot image. If that boot image is *not* your current kernel, find your kernel in synaptic (search for "linux-image") and mark it for reinstallation. Then reconfigure mdadm again and it should write to the correct boot image.

This all assumes you've got the correct mdadm config in the first place (correct mdadm.conf settings, valid fstab entry, etc). If you're still stuck, search the forums because there are lots of helpy bits there.