I've set up the new GateKeeper module. When I get the order email and click on the link (or paste it into a browser) it correctly downloads a zip file but the zip file is "corrupted". I did a binary compare of the actual file and the downloaded file and the difference is that the downloaded file has the HTML for a web page appended to the end of it. That is to say that he entire ZIP is there and correct, but the file contains a "suffix" of data that is raw HTML. It looks like it's probably a page on my site (I didn't try to scrape it to a separaste file to verify).
Any ideas on how to prevent this behavior?