yes, exactly, sorry for being unclear.
Here's what's written on it.
I've tried to upload a sketch with the Arduino IDE 1.0.5 after adding the bootloader from the the link above, selecting Atmega644P@16MHtz, but I get a :
avrdude: stk500_recv(): programmer is not responding
A long (~3s) press on the reset button is enough to set the board in flashing mode right?