Hi.. First of all, thank you for your answer!
Well. Lets see..
Are you certain that a powercycle or Reset does not restore operation and it really does require reprogramming?
No it doesn't. I can try to powercycle 100 times and doesn't work. at all.
The PROGMEM flash area is pretty robust
I'm not using any PROGMEM
Are you doing anything with high voltages that may be zapping the chip, such as with a relay, motor, or other inductive load?
No. I'm using to drive a display and a I2C sensor..
Do you have anything connected to the ISP pins that may be inadvertently putting the chip into programming mode?
Actually I don't know exactly... (wich pin are the ISP pin on atmega328?) honestly I don't know...
Are you using EEPROM in your program at all?
Yes to store some settings info.
Do you have decoupling caps on the VCC and ground pins?
No.. when turned on they are connected direct to the + and -
Do you have a pullup resistor on the Reset pin?
The Reset Pin us connected to + by a 5k resistor.
Please if you have any idea, please let me know..
Tks a lot!