This site downloading problem

I must be missing a setting somewhere but cannot find it. When I try to download any zip file from the download section here it opens in my save as download dialog box it appears as an email extension:

http://downloads.wordpress.org/plugin/stats.1.2.2.zip

shows up as

http://downloads.wordpress.org/plugin/stats.1.2.2.efw

Windows Vista machine.

This is the only place I have this problem.