Grumpy_Mike:
Because you can't do a reset from the boot loader, it involves resting some of the hardware that the bootloader will not be able to touch.
I'm not doing a reset from the bootloader, I'm doing a reset (via watchdog timer) to get to the bootloader, but I needed a new bootloader because the bootloader is so clever it knows a watchdog reset should just jump to the sketch rather than waiting for an upload.