I'm extracting a zip (self-extracting, but that probably doesn't matter) and for a few files I'm getting a dialog asking me if I want to replace a file that was already extracted with a file that's just about to be extracted. At first glance I didn't understand how a zip could contain the same file in the same place more than once. I then browsed to the file in question using 7zip (or any tool) and found this:
The difference is in the block number. What's actually happening here?