With the Alpha build i can make the camera "boot up", which means sometimes it gets past the canon logo (and see something in the viewfinder), sometimes not. CHDK is not loaded and the camera is pretty unresponsive (to turn it off i need to remove the SDCard first, then i can power it off.
I honestly don't know what I might be doing wrong, I am doing exactly the same what i did with my sx500is in february but its just not working. SDCard is recognized as bottable when I run stick again, i double checked if I am using the right build 8I (idn't at the first attempt, shame on me, there I got mixed up and actually tried to load the old CHDK for my sx500)