I fixed it!

It was a problem with my firewall.  I use "CA Antivirus" and one of the latest updates must have turned on the "email quarantine" for the .zip files.

I noticed that the download box was showing "email attachment" for the .ewf file.  I went to my firewall and played around with the email area.

There was a green checkmark next to all of the extensions so I clicked on the .zip one and looked in edit.  There was a box called "Quarantine all matching files", so I unchecked that and now I can download the .zip files here.  It's strange though that it wasn't affecting the .zip files at other sites, just this one.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi