Anyone familiar with tuning alerts on APC NMCs?

One of our UPSes is going insane, TENS OF THOUSANDS of alerts over the weekend and yesterday, and I can't figure out why I can't make it stop.

Within a minute I'll get dozens of alerts, hundreds an hour:
UPS on battery in response to a distorted input
UPS no longer on battery

They come in so fast the order gets jumbled. I have five other UPSes in the same room - not a peep.

Thing's I've tried:
-Disabling recipients for individual alerts
-Disabling recipients globally
-Adding a delay - first it was 30 seconds, then I tried five minutes, then I tried 720 minutes
-Setting repeats to longer and longer periods of time
-Disabling repeats
-Inputting hex codes for the alerts and the clearing alert and adjusting there

It looks like the log randomly cleared itself last night at 20:03:36 - we've had one hit that put it on battery since. On battery at 08:36:50, off battery at 08:37:04, alarm cleared. Other than that, the log is just my logins.

I'm logged in right now, no alarms. The on call phone on my desk is going nuts. The emails are easy, set up a rule and expect a call from security when they try to figure out what's happening to the mail server. The emails to text the cell phones are maddening.

I'm tempted to reset the thing to factory, give it a 169.x.x.x ip, unplug the ethernet cable and just depend on the other UPSes and the ATS to tell me we're off utility. I only need the thing to carry the load for a minute or two until the generator can get spun up.

Yes, I have the electricians looking at the circuit. Again, I have five other UPSes in that room, fed from the same box, just different breakers. It's even newer breakers, cables and jacks - had twist locks installed a couple of weeks ago.

For those of you about to Google, I've tried:
How To: Eliminate Superfluous "Critical" Alerts From APC Network Management Cards

Thoughts?

It's official, that thing is off the network and I'm replacing the NMC.

Fuck this noise.

Humorously, my folder for UPS alerts is 274MB, my ENTIRE inbox including subfolders is only 372MB. From one weekend. That's 98MB for all my other messages.

With the PowerChute software, you can lower the threashold/sensitvity for battery switching. Although, it sounds like either there's a real power quality problem, or the UPS is about to die.