Just in case you didn't know....
I had a sudden MFD failure today.
I've got an early '05, so I was worried that it was "the" failure, but the symptoms just didn't seem right. Slow response to button presses, messages that the air conditioner and GPS weren't connected... not the flaky reactions of the now-classic MFD failure.
A little searching over at priuschat.com turned up repeating mention that the DICE iPod interface can cause odd MFD behavior from time-to-time. So, I unplugged the little box, and all's well! I've moved it up into the glove compartment where it's more easily accessible so, when it happens again, it'll be easier to unplug on the go! Seems fine for now, but time will tell.
A little note to DICE iPod interface owners.