I had replaced the power supplies for the blade enclosures for a customer.  When they had all been replaced, I noticed that one enclosure had power warning for all but two blade servers.  I rebooted one thinking it would clear the alert, but it certainly did not.  I researched the issue on the HP website to no avail.  In desperation, I shut down the server blade completely, waited, and then restarted the server.  That finally cleared the warning.  I shut down the rest of the blades, and then turned them back on and all of the warnings had cleared.