Hi,
for the first 3 downloads you have used Internet Explorer, 4th download succeeded because you have used Mozilla Firefox for the file where Mozilla Firefox is
prefered (also possible with other browsers then IE, like Opera, Safari, Chrome...)
We apologize for the inconvenience, we are trying to have the download page browser independent. In this case we would have to disable gzip function on the web server for zip file types. In this moment we cannot do that, because of other reasons.
Best regards,
Viljem