Well, today I installed the replacement's replacement.
It lit off and ran for just over an hour and shut off when I told it to. It also turned on when asked too. I think the presence of the facility manager had something to do with its good behaviour.
But that doesn't mean there wasn't some fun. Ten minutes after I arrived the area suffered a brief power outage (rain got into an underground cable) and after hooking things up for a video system test, the company's laptop kept freezing up. (Blasted Win XP.)
We are now convinced that the room is possessed.
In the unlikely event the manufacturer of these fine specimens gives me a follow-up as to what failed in these supplies, I'll let you all know.
Have a safe one all.
Tony "The Xenon Exorcist"