UAC switching the user's passwords?

[faesce]

So the issue I'm having here is that my user accounts have sort of switched themselves. To clarify, my Administrator account had a password, my other user account did not. I woke up to find that the Administrator account no longer had a password, and the user account was now passworded with the administrator's! Now I can assure you that nobody is playing a practical joke, because I am the ONLY person who knows the Administrator password, therefore there is no way anyone else could set that exact password for the user account.

What in the world would cause this to happen? It was easy to fix, I just removed the password from the user account and re-set it on the Administrator one. However, I'd like for this to not happen any more, for obvious security reasons. What's the dealio?

 

[logicearth]

Never heard of that happening before...