dtluigi:
Problem solved!
I had an issue in the setup() of the board: when you declare the Serial.begin() only for debugging test, the board wants the PC to communicate with...without it, the board can't go on and then stop there!
That is not the problem, the board does not have to be connected to the PC to run a sketch that has already been uploaded to it. But perhaps the code in your sketch does not do anything useful unless if first receives something from the serial link?
Lefty