Hi
Yes, I did get that working by using an EEProm location.
It been awhile but near as I can tell from looking at (many versions) of the source code, it went something like this:
#include <EEPROM.h>
// in setup() include the following
//EEPROM.write(500,0); // only executed once to write the value permanently. comment out after one execution
max_msg = EEPROM.read(500);