1. if you have multiple sources for CFW PUP file always get the one that is Zip'd or Rar'd. Simply to ensure that the download finished properly. Sure the file inside could be bad, but at least you'll get warned if the archive is broken when you extract it.
2. I still meet people who blindly rip out usb-sticks from a windows pc. Really should use the "remove safely" button/icon so you are sure the whole file has been transferred properly. Alternatively close down the pc first before pulling anything.