On Sun, 26 Sep 2010, Mike Hartman wrote:

I've stopped /dev/md0 with "mdadm --stop /dev/md0" because I'm just
too worried about what might happen to the array if another component
mysteriously fails.

You need to start looking in dmesg / other logs to see what has happened 
and why things have failed. Without that information it's impossible to 
tell what's going on.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se