I thought i was too. Im telling you i banged my head against the wall for a week before i just said screw it and flashed all the way back. Just telling you how i finally got it to work. Take it or leave it.
The issue I had and later figured out was that the phone wasn't completely wiped in the /preinstall folder. If you hit the volume up and down buttons while it's installing it will show you the step it's going through and should show you any errors. I ended up flashing back to .744 and using the OTA updates to .173 then installing the leak. Right before I did I checked to make sure there wasn't anything in the /preinstall folder and of course, flashed the ICS leak.