Weird password issue

So, all of the sudden, I couldn't access the foums using my current password. One that I had assigned not long ago when the notices were sent out.

I got in twice today but when I attempted to sign in the third time, it told me my password was incorrect. I of course tried a few more times but...nothing.

Then I clicked in the area to reset the password, received the email, clicked the link and came to the password reset screen. All good so far.

For giggles, I entered my previous password. It gave me the message that I could not use the old password. So then I used my current password and it was fine.

So what it looks like is, my account reverted to an old password. How could that happen?