uhm........28924 bytes (of a 30720 byte maximum). I think that the bootloader use max 2k of memory. With the sketch size of 28924 bytes i can't upload sketch. does anyone know the size of optiboot bootloader? It is in a subdir of arduino ide.I've a old bootloader version and i try to upgrade it. Read posts in this link: http://www.forums.adafruit.com/viewtopic.php?f=31&t=19243