The manual loading method does work, but it might take 3 or 4 attempts. You need to press the power button right around the time the screen turns black after OK'ing the firmware upgrade. I'm using the version from post 467 all the time.
Apart from that, run SDMinst on your PC to set up the SD card. It'll create the two partitions, mark one bootable and allow you to swap between the two. When you finish up, you'll have discboot.bin on the smaller fist partition, which itself marked bootable. The second larger partition will have the chdk directory/files.