I've encountered a field failure where ATmega32 chips are returning undamaged with just their FLASH memory erased, but not their EEPROM. The program fuses set/cleared and program memory is erased as though the studio had been used to erase the part pending reprogramming. We know EEPROM doesn't get erased as OSCAL byte still holds the initial calibration value. The customer's application board does not support any field programming or debugging - no JTAG or debug connections brought out.
What I am looking for is not so much a diagnosis as any experience with similar Flash (not EEPROM) loss. Atmel has contributed one similar instance, but I need to know if anyone on the forum has seen anything like this and, ideally, if you were able to fix the problem.