Having a need to reset a FireBall DVDM-100 to factory defaults, Escient support told me I could accomplish this via a hidden "Advanced Utilities" menu within setup. Having spent a lot of time searching the AVS (and other) forums for this useful information, I thought I would pass it along.

To access the 'Setup - Advanced Utilities' screen (for ALL the FireBall models, apparently), do the following:

Go to the setup screen.
Enter the numeric sequence 8020.

This brings up a screen with the following selections:

Restore factory defaults
Force reregistration (restarts unit)
Library index rebuild (restarts unit)
Lookup all music coverart
Lookup all movie coverart
Exit