Casio CZ/ VZ/ FZ - Pro Series

Hey there.

So I've got a CZ-1000. It's served me very well, had it about 2 years 
now.

Something strange has happened recently, though: there are no batteries 
in the keyboard, so I use an AC adapter (plug it into the wall). I turn 
on the keyboard, and everything is transposed five notes up!

By that, I mean that what should be my black G# key now plays E. Very 
strange.

The keyboard plays fine, but everything is transposed five notes up.

I know there's that little button on the back that resets everything to 
the factory standards. Do I need to have batteries inside for this to 
work? The CZ-1000 manual says that the keyboard must be ON while you 
press this button; am I missing something?

Let me know what you think.