I still have issues with your sketch. The auto reset works fine, I can see that on the scope, see attached image. The reset line is green and is released once DTR is triggered, letting the slave Arduino run it's bootloader. (Which it does.). Shortly after that, the blue line (Leonardo TX) issues 3 requests to the bootloader of the slave Arduino, which does not respond. So the upload fails. Right now I have no idea why. If I use the regular USB connection of the slave Arduino, it works. I'd once been able to flash my Duemilanove with an external FTDI, but for some reason, that also fails now.
