This prevents the +10vdc pulse from the auto-reset cap from causing the problem stated in this thread ... consistently make the 328 chip power up into some kind of 'locked-up' condition
Enter Programming Mode ... 3. Wait 20 - 60 ?s, and apply 11.5 - 12.5V to RESET.
I suspect the "locked-up" condition is parallel programming mode. I wonder if that's how the bootloader gets erased?