"I just needed to update my version of MS Word for Mac and had a real problem installing the XML reader," begins De Prez Allen Laudenslager. He goes on to explain the problem and the solution. "When I contacted Microsoft for help, they told me that using Firefox might be the problem.
"While this sounds weird, the tech 'thinks' that Firefox somehow doesn't always properly attach the correct file extension name. Word documents are .doc and updates to applications are disk image files .dmg, etc. That file name extension allows Mac OS and the various applications to decide how to handle the file. One example would be when you double click on the file your Mac knows to open the file in your word processor or in iPhoto or whatever.
"I went back to the site (mactopia.com) using Safari and downloaded the file a second time and was able to properly install the update and open the latest MS Word version files with the extension .docx.
"Just one more trick to keep in mind if you are having trouble downloading files using Firefox as your primary web browser."