We had the same issues with Navicore and I asked them back in the day to host the files directly.

Here's an email I've just fired off to them:
There are many issues with the download servers which means it's very difficult to obtain the Wayfinder maps at the best of times.

Please can you host the files directly on your webservers like Navicore did here: http://www.navicoretech.com/Consumer.../en_GB/tablet/

Hope to hear from you soon.

Many thanks!