F16: Raid1 /home failing to restart cleanly

['Chris Hall']

I have a /home partition which is set up as a Software RAID1, using /dev/md0.

When I reboot the /dev/md0 fails to come up cleanly.  So far it has come back each time, but nearly every time it comes up with one of the two members of the RAID array missing.  I can mdadm /dev/md0 --re-add /dev/sdb3 -- and all is apparently well again.  But I have this partition as RAID for a reason, and it scares the bejazus out of me each time :-(

Any clues as to what spells I have failed to cast ?

Thanks,

Chris