Notice the capital "U" on "Update.zip" ? I wonder if that was my flashing problem for this user's guide?
I named mine update.zip while S-ON and it worked fine, don't think it matters. One thing we sort of theorized while helping another poster who was having trouble getting the first ICS OTA update to install was that you need to clear the phone cache from the stock recovery before trying to flash the first update.zip (and then again before you try to install the second.)
Glad you got it work the automated way. The above tip probably needs to be done for the OTApkg, but I'm going to let Scotty test it out first