Outlook Web Access, XLSX when saved, saved as ZIP

So I had an issue where someone was downloading an Office 2007 XLSX file in Outlook web access (OWA)... it would download as a zip file.  I found that by adding that webmail address to the trusted sites in internet explorer fixed the problem.

OS: Windows XP
Problem: IE8
Solution:  Click start -> Settings -> Control Panel -> Internet Options -> Security -> Trusted Sites -> Click Sites -> type the website and click add.