A fair chance it was the latter.

There is a rare and intermittant bug with some empegs/installations where the empeg starts up all on its own and the stereo system plays merrily away until the battery voltage drops down to around 10-11 volts, at which time the empeg quits due to low voltage.

The engine in my car is old enough and loose enough that it will still start when there isn't enough voltage to run my empeg, but that is an unusual circumstance.

As to why your empeg settings were lost... no idea unless it was a byproduct of low voltage when the player finally stopped.

tanstaafl.