sparkfun mini usb + Sparkfun arduino mini ( with AT328 and unknowed bootloader ) : same issue, same results...
I have looked carefully on arduino pro 5V to apply the same schematic ( reset , supply , DTR connection ) on these arduino mini .
I use arduino software with arduino pro 5V 16 Mhz setting : upload start..and nothing append.
Next step : upload bootloader from arduino software, and try again. I'm waiting my tinyusb board.I have choosed these Sparkfun solution to have efficienty hardware solution : it is not : A lot of time loosed...