At EXACTLY 10am, every day, I get in my event log:

Event ID: 12294
"The SAM Database was unable to lockout the account of [] due to a resource error, such as a hard disk write failure ( the specific error code is in the error data). Accounts are locked after a certain number of bad passwords are provided so please consider resetting the password of the account mentioned above."

Trouble is - I have no user account "[]". (it's a little box) I've searched AD with no results. It happens on all my domain controllers at the same time, so I doubt its a hardware problem.

I am having NO luck finding a decent resolution to this error. I can provide the Hex error data if you're interested.
Any help would be greatly appreciated!