I'm surprised you didn't see it yourself. The game comes announcing that game.dat was changed, and you did that by copying the crack over before updating the last time. At least that's what's in your post. Simply reinstall, either run the 1.3 patch or the in-game updater (which should go straight from 1.0 to the latest version) and then apply the crack. The problem I fear will be the last bit. It seems like there was yet another new patch for generals, and I'm sure I haven't seen any crack for it yet. So in future, always make sure you've got the original executable before trying to update, lotsa patches check this.
Now you could wait until the new crack comes out (won't be too long I think), or you can use Alcohol120% to play from a hard disk image and insure that you never need a crack anymore. It seems like c&c generals is a game that gets updated a lot, so if you do it this way, you might spare yourself quite some effort and trouble down the road. It's your call
