Hmmmmm, I am curious to the cause. If it wasn't the operator settings and the registry wasn't corrupted, this is weird. I will likely mull it over trying to figure it out today. I run into weird stuff all the time at work and it is good to know how to fix it when something comes up.
It is always awesome when your boss spends half a day trying to fix something and you come in and are done in seconds. I keep a log of weird issues and their fixes for this reason. One of my coworkers gets pissed when he spends days on something and then I come in and it is done. He has changed his tactics to just ask me before he spends time on it.
My philosophy on it is the sooner I get it running the sooner production is running again. So lets get it done and get out of the way.