In mdadm-1.5.0-2, there's apparently a new mdmpd daemon and service but no documentation for what it is, how to administer it, etc.
I've added a man page as of 1.5.0-9.
An errata has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2004-226.html