If you were editing the inis remove the changed ones from the game dir and try again. have you deleted or replaced any of the bigs? this would probably cause a problem.
I've saved all the downloads that I've gotten from the Auto Update, then I unistalled the game and reinstalled it and copied all the patches to the patches directory in the generals installation dir. Then it started updating the I got this message on the third patch!
So, the game was still patched to 1.4 and seems to work, so I have no idea why I got this..