The message is an indication that a hard reset has occurred. A hard reset erases only the information you have stored. It does not remove Newton's programs or operating system software (including system updates).
The normal procedure for doing a hard reset is to slide down the on/off switch, hold it down as you press the Reset button in the battery compartment, and then release the on/off switch.
There are also two unusual situations that can trigger a hard reset. If the Newton MessagePad is low on power, then a power fault flag is set. Once this flag is set, if the power switch is held for an extended duration, a hard reset is triggered. If the Newton MessagePad quits and resets itself, and the power switch is held down, a hard reset is also triggered.
No changes will be made to the software or hardware to eliminate this from occurring.