Our site was experiencing problems with map downloads recently. The problem only occurred for users of Internet Explorer 7 and did not affect Firefox downloads.

If you downloaded a map and tried to open the zip file, you would have gotten an error saying that the zip file was corrupted. The was because our server is using GZIP to optimize HTTP transfer speeds; unfortunately, GZIP will zip up content that is already zipped up if the content is generated by a server script (in this case, a PHP script).

If you want to re-download a map file that you previously downloaded, you will have either delete your browser cookies or download the map with another browser (such as Firefox).