Same #SysAdmin vibe here!
The mail server on which the power supply died had been rebooting spontaneously and hanging on startup a couple of times a day, and I spent a lot of time sifting through the logs to see what might be triggering it. I finally scripted a bunch of startup scripts to send an alert, circumvent the hang, restart the mail services, and just let it do its reboot thing.
With the new PS it seems to be stable. Was it a bad power supply all along? We'll never know now...