I've ODIN'd several files to my very not stock Fascinate, as well as doing what the OP described to get the official Froyo (and then root it). If you're using a desktop, you will be better off using a rear USB port, as they are attached to the mother board, rather than via a cable. With a laptop, make sure you're connecting the original USB cable (desktop too for that) that came with the phone to a port on the laptop itself, not a hub, as those tend to lead to communication issues between the PC and phone. And installing the drivers FIRST is a must, as ODIN cannot properly see your phone without them. The joy of ODIN is that even if you mess up a bit and your phone won't turn on, so long as you have a stable stock ROM to flash, you can almost always get back to download mode and essentially reset your phone.